/* ═══════════════════════════════════════════════════════════════
   ADDISSEC CTF — MAIN STYLESHEET
   Responsive for all devices, preserving original UI design
═══════════════════════════════════════════════════════════════ */

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-bg:     #0a0a0f;
    --secondary-bg:   #0f0f1a;
    --card-bg:        rgba(18, 22, 35, 0.85);
    --primary-neon:   #00ff9d;
    --secondary-neon: #00a8ff;
    --tertiary-neon:  #8a2be2;
    --text-primary:   #ffffff;
    --text-secondary: #b0b0b0;
    --border-glow:    rgba(0, 255, 157, 0.25);
    --glow-shadow:    0 0 12px rgba(0, 255, 157, 0.4);
    --transition:     all 0.4s cubic-bezier(0.2, 0.9, 0.4, 1.1);
    --gold:           #fbbf24;
    --silver:         #94a3b8;
    --bronze:         #cd7f32;
    --header-height:  70px;
    --danger:         #ff4444;
    --success:        #00ff9d;
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    background-image:
        radial-gradient(circle at 15% 30%, rgba(0,255,157,0.03) 0%, transparent 35%),
        radial-gradient(circle at 85% 70%, rgba(0,168,255,0.03) 0%, transparent 40%);
}

h1, h2, h3, h4 {
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    letter-spacing: -0.02em;
}

img { max-width: 100%; display: block; }

/* ─── SCROLLBAR ─── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--primary-bg); }
::-webkit-scrollbar-thumb { background: var(--border-glow); border-radius: 3px; }

/* ─── CONTAINER ─── */
.container {
    width: min(90%, 1280px);
    margin: 0 auto;
    padding: 0 20px;
}

/* ═══════════════════════════════════════════════════════════════
   BUTTONS
═══════════════════════════════════════════════════════════════ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px 28px;
    font-family: 'Orbitron', sans-serif;
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    background: transparent;
    text-decoration: none;
    white-space: nowrap;
}
.btn-sm { padding: 8px 18px; font-size: 0.72rem; }
.btn-primary {
    border-color: var(--primary-neon);
    color: var(--primary-neon);
    box-shadow: 0 0 8px rgba(0,255,157,0.3);
}
.btn-primary:hover {
    background: var(--primary-neon);
    color: var(--primary-bg);
    box-shadow: 0 0 20px var(--primary-neon);
    transform: translateY(-2px);
}
.btn-secondary {
    border-color: var(--secondary-neon);
    color: var(--secondary-neon);
}
.btn-secondary:hover {
    background: var(--secondary-neon);
    color: var(--primary-bg);
    box-shadow: 0 0 20px var(--secondary-neon);
    transform: translateY(-2px);
}
.btn-ghost {
    border-color: rgba(255,255,255,0.15);
    color: var(--text-secondary);
}
.btn-ghost:hover {
    border-color: var(--primary-neon);
    color: var(--primary-neon);
}
.btn-danger {
    border-color: var(--danger);
    color: var(--danger);
}
.btn-danger:hover {
    background: var(--danger);
    color: #fff;
}

/* ═══════════════════════════════════════════════════════════════
   HEADER
═══════════════════════════════════════════════════════════════ */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(10,10,15,0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-glow);
    transition: background 0.3s;
}
.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
    gap: 16px;
    flex-wrap: nowrap;
    min-width: 0;
}
.header-container .logo    { flex-shrink: 0; min-width: 0; }
.header-container nav      { flex: 1; }
.header-container .header-auth { flex-shrink: 0; }
.header-container .mobile-menu-btn { flex-shrink: 0; }
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}
.logo-img {
    height: 42px;
    width: auto;
    border-radius: 8px;
    object-fit: contain;
}
.logo-text {
    font-family: 'Orbitron', sans-serif;
    font-weight: 800;
    font-size: 1.3rem;
    white-space: nowrap;
}
.logo-text span { color: #ffffff; }
.logo-white { color: #ffffff !important; }
.logo-green { color: var(--primary-neon) !important; }

/* ─── NAV ─── */
nav ul {
    display: flex;
    list-style: none;
    gap: 28px;
    align-items: center;
}
nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: 0.88rem;
    white-space: nowrap;
}
nav a:hover, nav a.active {
    color: var(--primary-neon);
    transform: translateY(-1px);
}

/* ─── HEADER AUTH ─── */
.header-auth {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
    min-width: 0;
    overflow: hidden;
}
.auth-buttons {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: nowrap;
    min-width: 0;
}
.user-pill {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(0,255,157,0.08);
    border: 1px solid rgba(0,255,157,0.25);
    border-radius: 40px;
    padding: 6px 14px 6px 10px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}
.user-pill:hover { border-color: var(--primary-neon); background: rgba(0,255,157,0.12); }
.user-pill-name {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.62rem;
    color: var(--primary-neon);
    max-width: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.user-pill-pts {
    font-family: 'Orbitron', monospace;
    font-size: 0.62rem;
    color: var(--gold);
    display: flex;
    align-items: center;
    gap: 3px;
}
.user-dropdown {
    display: none;
    position: absolute;
    top: calc(var(--header-height) - 4px);
    right: 0;
    background: #0c0f1c;
    border: 1px solid var(--border-glow);
    border-radius: 14px;
    padding: 10px;
    min-width: 180px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    z-index: 1001;
}
.user-dropdown.open { display: block; animation: dropIn 0.2s ease; }
@keyframes dropIn {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
}
.user-dropdown a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 12px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.82rem;
    border-radius: 8px;
    transition: all 0.2s;
}
.user-dropdown a:hover { background: rgba(0,255,157,0.08); color: var(--primary-neon); }

/* ─── MOBILE MENU BUTTON ─── */
.mobile-menu-btn {
    display: none;
    background: none;
    border: 1px solid var(--border-glow);
    color: var(--text-primary);
    font-size: 1.1rem;
    cursor: pointer;
    padding: 8px 10px;
    border-radius: 8px;
    transition: var(--transition);
    order: 3;
}
.mobile-menu-btn:hover { border-color: var(--primary-neon); color: var(--primary-neon); }

/* ═══════════════════════════════════════════════════════════════
   FLASH MESSAGES
═══════════════════════════════════════════════════════════════ */
.flash-container {
    position: fixed;
    top: calc(var(--header-height) + 12px);
    right: 16px;
    z-index: 9000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-width: min(380px, calc(100vw - 32px));
}
.flash {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-radius: 12px;
    font-size: 0.84rem;
    border: 1px solid;
    animation: slideInRight 0.3s ease;
    backdrop-filter: blur(8px);
}
@keyframes slideInRight {
    from { opacity: 0; transform: translateX(40px); }
    to   { opacity: 1; transform: translateX(0); }
}
.flash-success { background: rgba(0,255,157,0.12); border-color: rgba(0,255,157,0.35); color: var(--primary-neon); }
.flash-error   { background: rgba(255,68,68,0.12);  border-color: rgba(255,68,68,0.35);  color: #ff8888; }
.flash-info    { background: rgba(0,168,255,0.12); border-color: rgba(0,168,255,0.35); color: var(--secondary-neon); }
.flash-close {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    margin-left: auto;
    opacity: 0.7;
    font-size: 0.9rem;
}
.flash-close:hover { opacity: 1; }

/* ═══════════════════════════════════════════════════════════════
   GLITCH TEXT
═══════════════════════════════════════════════════════════════ */
.glitch-text {
    position: relative;
    display: inline-block;
}
.glitch-text::before,
.glitch-text::after {
    content: attr(data-text);
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
}
.glitch-text::before {
    left: 2px;
    text-shadow: -2px 0 #ff00c1;
    clip: rect(44px, 450px, 56px, 0);
    animation: glitch-anim 5s infinite linear alternate-reverse;
}
.glitch-text::after {
    left: -2px;
    text-shadow: -2px 0 #00fff9;
    clip: rect(44px, 450px, 56px, 0);
    animation: glitch-anim2 5s infinite linear alternate-reverse;
}
@keyframes glitch-anim {
    0%  { clip: rect(42px,9999px,44px,0); }  5%  { clip: rect(12px,9999px,59px,0); }
    10% { clip: rect(48px,9999px,29px,0); }  15% { clip: rect(42px,9999px,73px,0); }
    20% { clip: rect(63px,9999px,27px,0); }  25% { clip: rect(34px,9999px,55px,0); }
    30% { clip: rect(86px,9999px,73px,0); }  35% { clip: rect(20px,9999px,20px,0); }
    40% { clip: rect(26px,9999px,60px,0); }  45% { clip: rect(25px,9999px,66px,0); }
    50% { clip: rect(57px,9999px,98px,0); }  55% { clip: rect(5px,9999px,46px,0); }
    60% { clip: rect(82px,9999px,31px,0); }  65% { clip: rect(54px,9999px,27px,0); }
    70% { clip: rect(28px,9999px,99px,0); }  75% { clip: rect(45px,9999px,69px,0); }
    80% { clip: rect(23px,9999px,85px,0); }  85% { clip: rect(54px,9999px,84px,0); }
    90% { clip: rect(45px,9999px,47px,0); }  95% { clip: rect(37px,9999px,20px,0); }
    100%{ clip: rect(4px,9999px,91px,0); }
}
@keyframes glitch-anim2 {
    0%  { clip: rect(65px,9999px,100px,0); } 5%  { clip: rect(52px,9999px,74px,0); }
    10% { clip: rect(79px,9999px,85px,0); }  15% { clip: rect(75px,9999px,5px,0); }
    20% { clip: rect(67px,9999px,61px,0); }  25% { clip: rect(14px,9999px,79px,0); }
    30% { clip: rect(1px,9999px,66px,0); }   35% { clip: rect(86px,9999px,30px,0); }
    40% { clip: rect(23px,9999px,98px,0); }  45% { clip: rect(85px,9999px,72px,0); }
    50% { clip: rect(71px,9999px,75px,0); }  55% { clip: rect(2px,9999px,48px,0); }
    60% { clip: rect(30px,9999px,16px,0); }  65% { clip: rect(59px,9999px,50px,0); }
    70% { clip: rect(41px,9999px,62px,0); }  75% { clip: rect(2px,9999px,82px,0); }
    80% { clip: rect(47px,9999px,73px,0); }  85% { clip: rect(3px,9999px,27px,0); }
    90% { clip: rect(26px,9999px,55px,0); }  95% { clip: rect(42px,9999px,97px,0); }
    100%{ clip: rect(38px,9999px,49px,0); }
}

/* ═══════════════════════════════════════════════════════════════
   HERO SECTION
═══════════════════════════════════════════════════════════════ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: calc(var(--header-height) + 16px);
    position: relative;
}
.hero-inner {
    display: grid;
    grid-template-columns: 1fr;
    gap: 48px;
    align-items: center;
    padding: 60px 0 80px;
    width: 100%;
}
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(0,255,157,0.1);
    border: 1px solid var(--border-glow);
    padding: 6px 18px;
    border-radius: 40px;
    font-size: 0.72rem;
    font-family: 'Orbitron', monospace;
    color: var(--primary-neon);
    margin-bottom: 24px;
    animation: fadeUp 0.8s ease;
}
.hero h1 {
    font-size: clamp(2rem, 5.5vw, 4rem);
    line-height: 1.1;
    margin-bottom: 20px;
    animation: fadeUp 0.8s ease 0.1s both;
}
.hero h1 .accent {
    color: var(--primary-neon);
    text-shadow: 0 0 8px rgba(0,255,157,0.5);
}
.hero p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 540px;
    margin-bottom: 32px;
    animation: fadeUp 0.8s ease 0.2s both;
    line-height: 1.7;
}
.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 52px;
    animation: fadeUp 0.8s ease 0.3s both;
}
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ─── COUNTDOWN ─── */
.countdown {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}
.countdown-card {
    background: var(--card-bg);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-glow);
    border-radius: 16px;
    padding: 18px 22px;
    text-align: center;
    min-width: 88px;
    transition: var(--transition);
}
.countdown-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-neon);
    box-shadow: var(--glow-shadow);
}
.countdown-num {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.3rem;
    font-weight: 800;
    color: var(--primary-neon);
    line-height: 1;
}
.countdown-label {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-secondary);
    margin-top: 6px;
}

/* ═══════════════════════════════════════════════════════════════
   STATS STRIP
═══════════════════════════════════════════════════════════════ */
.stats-strip {
    background: var(--secondary-bg);
    border-top: 1px solid var(--border-glow);
    border-bottom: 1px solid var(--border-glow);
    padding: 48px 0;
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
}
.stat-item {
    display: flex;
    align-items: center;
    gap: 16px;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}
.stat-item.animate { opacity: 1; transform: translateY(0); }
.stat-icon {
    width: 52px;
    height: 52px;
    background: rgba(0,255,157,0.1);
    border: 1px solid var(--border-glow);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    color: var(--primary-neon);
    flex-shrink: 0;
}
.stat-info h3 { font-size: 1.8rem; margin-bottom: 4px; }
.stat-info p  { font-size: 0.78rem; color: var(--text-secondary); }

/* ═══════════════════════════════════════════════════════════════
   SECTION HEADER
═══════════════════════════════════════════════════════════════ */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}
.section-tag {
    display: inline-block;
    background: rgba(0,255,157,0.1);
    color: var(--primary-neon);
    padding: 5px 16px;
    border-radius: 40px;
    font-size: 0.68rem;
    font-family: 'Orbitron', monospace;
    margin-bottom: 16px;
}
.section-header h2 {
    font-size: clamp(1.7rem, 4vw, 2.4rem);
    margin-bottom: 12px;
}

/* ═══════════════════════════════════════════════════════════════
   ELITE HUNTERS / PROFILES SECTION
═══════════════════════════════════════════════════════════════ */
.profiles-elite { padding: 80px 0; }
.elite-grid {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}
.elite-card {
    background: linear-gradient(145deg, rgba(12,15,28,0.95), rgba(8,10,20,0.98));
    backdrop-filter: blur(12px);
    border-radius: 36px;
    width: 340px;
    max-width: 100%;
    padding: 32px 24px;
    text-align: center;
    border: 1px solid rgba(0,255,157,0.3);
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
    animation: floatIn 0.7s ease backwards;
}
.elite-card:nth-child(1) { animation-delay: 0.1s; }
.elite-card:nth-child(2) { animation-delay: 0.2s; }
.elite-card:nth-child(3) { animation-delay: 0.3s; }
@keyframes floatIn {
    from { opacity: 0; transform: translateY(40px); }
    to   { opacity: 1; transform: translateY(0); }
}
.elite-card:hover {
    transform: translateY(-12px);
    border-color: var(--primary-neon);
    box-shadow: 0 0 40px rgba(0,255,157,0.25);
}
.elite-avatar {
    width: 130px;
    height: 130px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: linear-gradient(135deg, #0a1a1a, #001515);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 3px solid var(--primary-neon);
    box-shadow: 0 0 25px rgba(0,255,157,0.4);
    overflow: hidden;
    transition: transform 0.3s;
}
.elite-card:hover .elite-avatar { transform: scale(1.05); }
.elite-avatar svg { width: 100%; height: 100%; }
.elite-rank-badge {
    position: absolute;
    top: 18px;
    right: 18px;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Orbitron', sans-serif;
    font-size: 0.7rem;
    font-weight: 700;
}
.rank-gold   { background: rgba(251,191,36,0.15); border: 1px solid var(--gold);   color: var(--gold);   }
.rank-silver { background: rgba(148,163,184,0.15);border: 1px solid var(--silver); color: var(--silver); }
.rank-bronze { background: rgba(205,127,50,0.15); border: 1px solid var(--bronze); color: var(--bronze); }
.elite-name {
    font-size: 1.6rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-neon), var(--secondary-neon));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 10px;
}
.elite-title {
    font-size: 0.72rem;
    color: var(--text-secondary);
    letter-spacing: 2px;
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.elite-bio {
    font-size: 0.85rem;
    color: #ccc;
    margin-bottom: 22px;
    line-height: 1.55;
}
.elite-stats {
    display: flex;
    justify-content: space-between;
    background: rgba(0,255,157,0.07);
    border-radius: 50px;
    padding: 10px 18px;
    font-size: 0.78rem;
    flex-wrap: wrap;
    gap: 6px;
}
.elite-stats span i { margin-right: 5px; color: var(--primary-neon); }

/* ═══════════════════════════════════════════════════════════════
   CATEGORIES GRID
═══════════════════════════════════════════════════════════════ */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 22px;
}
.cat-card {
    background: var(--card-bg);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-glow);
    border-radius: 16px;
    padding: 26px;
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
}
.cat-card.animate { opacity: 1; transform: translateY(0); }
.cat-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-neon);
    box-shadow: var(--glow-shadow);
}
.cat-icon {
    width: 52px;
    height: 52px;
    background: rgba(0,255,157,0.1);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-neon);
    margin-bottom: 18px;
}
.cat-count {
    font-size: 0.72rem;
    color: var(--primary-neon);
    margin-bottom: 8px;
    font-family: 'Orbitron', monospace;
}
.cat-card p { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.55; }

/* ═══════════════════════════════════════════════════════════════
   CHALLENGES GRID
═══════════════════════════════════════════════════════════════ */
.challenges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 22px;
}
.chal-card {
    background: var(--card-bg);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-glow);
    border-radius: 16px;
    padding: 24px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(30px);
}
.chal-card.animate { opacity: 1; transform: translateY(0); }
.chal-card:not(.blur-challenge)::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 3px;
    background: linear-gradient(90deg, var(--primary-neon), var(--secondary-neon));
}
.chal-card:not(.blur-challenge):hover {
    transform: translateY(-6px);
    border-color: var(--primary-neon);
    box-shadow: var(--glow-shadow);
    cursor: pointer;
}
.blur-challenge {
    filter: blur(3px);
    pointer-events: none;
    user-select: none;
    background: rgba(10,10,18,0.8);
    opacity: 0.8;
}
.chal-card.solved::after {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 3px;
    background: linear-gradient(90deg, var(--gold), #f59e0b);
}
.chal-card.solved { border-color: rgba(251,191,36,0.3); }
.solved-badge {
    position: absolute;
    top: 14px;
    right: 14px;
    background: rgba(251,191,36,0.15);
    border: 1px solid rgba(251,191,36,0.4);
    color: var(--gold);
    font-size: 0.6rem;
    padding: 3px 8px;
    border-radius: 20px;
    font-family: 'Orbitron', monospace;
    display: flex;
    align-items: center;
    gap: 4px;
}
.chal-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 14px;
}
.chal-cat {
    font-size: 0.66rem;
    padding: 4px 11px;
    border-radius: 20px;
    background: rgba(0,255,157,0.12);
    color: var(--primary-neon);
    font-family: 'Orbitron', monospace;
}
.chal-points {
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    font-size: 0.88rem;
    color: var(--secondary-neon);
}
.chal-card h3 { font-size: 1rem; margin-bottom: 10px; }
.chal-desc {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 18px;
    line-height: 1.6;
}
.chal-desc strong { color: #fff; font-weight: 600; }
.chal-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}
.chal-footer span { font-size: 0.76rem; color: var(--text-secondary); }
.difficulty {
    font-size: 0.66rem;
    padding: 4px 11px;
    border-radius: 20px;
    font-family: 'Orbitron', monospace;
}
.difficulty-Easy   { background: rgba(0,255,157,0.12);  color: var(--primary-neon); }
.difficulty-Medium { background: rgba(0,168,255,0.12);  color: var(--secondary-neon); }
.difficulty-Hard   { background: rgba(138,43,226,0.12); color: var(--tertiary-neon); }
.difficulty-Expert { background: rgba(255,68,68,0.12);  color: #ff8888; }

/* ═══════════════════════════════════════════════════════════════
   CTA BANNER
═══════════════════════════════════════════════════════════════ */
.cta-banner {
    background: linear-gradient(135deg, rgba(0,255,157,0.05), rgba(0,168,255,0.05));
    border-top: 1px solid var(--border-glow);
    border-bottom: 1px solid var(--border-glow);
    padding: 70px 0;
    text-align: center;
}
.cta-banner h2 { font-size: clamp(1.7rem,4vw,2.4rem); margin-bottom: 14px; }
.cta-banner p  { color: var(--text-secondary); margin-bottom: 28px; font-size: 1rem; }
.cta-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

/* ═══════════════════════════════════════════════════════════════
   SCOREBOARD PAGE
═══════════════════════════════════════════════════════════════ */
.page-wrap { padding-top: calc(var(--header-height) + 24px); }
.page-section { padding: 60px 0; }
.scoreboard-table-wrap {
    background: var(--card-bg);
    border: 1px solid var(--border-glow);
    border-radius: 20px;
    overflow: hidden;
}
.scoreboard-table {
    width: 100%;
    border-collapse: collapse;
}
.scoreboard-table thead tr {
    background: rgba(0,255,157,0.06);
    border-bottom: 1px solid var(--border-glow);
}
.scoreboard-table th {
    padding: 14px 18px;
    text-align: left;
    font-family: 'Orbitron', sans-serif;
    font-size: 0.68rem;
    color: var(--primary-neon);
    letter-spacing: 1px;
}
.scoreboard-table td {
    padding: 14px 18px;
    font-size: 0.88rem;
    border-bottom: 1px solid rgba(255,255,255,0.04);
    color: var(--text-secondary);
}
.scoreboard-table tbody tr:last-child td { border-bottom: none; }
.scoreboard-table tbody tr:hover td { background: rgba(0,255,157,0.03); }
.scoreboard-table tbody tr.my-row td {
    background: rgba(0,255,157,0.06);
    color: var(--primary-neon);
}
.rank-cell { font-family: 'Orbitron', sans-serif; font-weight: 700; font-size: 1rem; }
.rank-1 { color: var(--gold); }
.rank-2 { color: var(--silver); }
.rank-3 { color: var(--bronze); }
.username-cell {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    color: var(--text-primary);
}
.user-avatar-icon {
    width: 34px;
    height: 34px;
    background: rgba(0,255,157,0.1);
    border: 1px solid var(--border-glow);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    color: var(--primary-neon);
    flex-shrink: 0;
}
.pts-cell {
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    color: var(--secondary-neon);
}
.my-rank-banner {
    background: rgba(0,255,157,0.08);
    border: 1px solid rgba(0,255,157,0.25);
    border-radius: 14px;
    padding: 14px 20px;
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}
.my-rank-banner .rank-num {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--primary-neon);
}
.my-rank-banner p { color: var(--text-secondary); font-size: 0.84rem; }

/* ═══════════════════════════════════════════════════════════════
   PROFILE PAGE
═══════════════════════════════════════════════════════════════ */
.profile-hero {
    padding: 50px 0 40px;
    border-bottom: 1px solid var(--border-glow);
}
.profile-header {
    display: flex;
    align-items: center;
    gap: 28px;
    flex-wrap: wrap;
}
.profile-avatar {
    width: 90px;
    height: 90px;
    background: rgba(0,255,157,0.1);
    border: 2px solid var(--primary-neon);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.4rem;
    color: var(--primary-neon);
    flex-shrink: 0;
    box-shadow: 0 0 20px rgba(0,255,157,0.25);
}
.profile-info h2 { font-size: 1.8rem; margin-bottom: 6px; }
.profile-info p  { color: var(--text-secondary); font-size: 0.88rem; }
.profile-meta {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 12px;
}
.meta-pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(0,255,157,0.07);
    border: 1px solid var(--border-glow);
    padding: 5px 14px;
    border-radius: 40px;
    font-size: 0.72rem;
    color: var(--text-secondary);
}
.meta-pill i { color: var(--primary-neon); font-size: 0.7rem; }
.stats-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
    margin: 32px 0;
}
.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--border-glow);
    border-radius: 16px;
    padding: 20px;
    text-align: center;
    transition: var(--transition);
}
.stat-card:hover { border-color: var(--primary-neon); box-shadow: var(--glow-shadow); }
.stat-card .num {
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-neon);
    line-height: 1.1;
    margin-bottom: 4px;
}
.stat-card .lbl { font-size: 0.72rem; color: var(--text-secondary); }
.solved-list { display: flex; flex-direction: column; gap: 12px; }
.solved-item {
    background: var(--card-bg);
    border: 1px solid var(--border-glow);
    border-radius: 14px;
    padding: 16px 18px;
    display: flex;
    align-items: center;
    gap: 14px;
    flex-wrap: wrap;
    transition: var(--transition);
}
.solved-item:hover { border-color: rgba(251,191,36,0.4); }
.solved-item .chal-name { font-weight: 600; color: var(--text-primary); flex: 1; min-width: 120px; }
.solved-item .pts-label {
    font-family: 'Orbitron', monospace;
    font-size: 0.75rem;
    color: var(--gold);
    background: rgba(251,191,36,0.1);
    padding: 3px 10px;
    border-radius: 20px;
}
.solved-item .time-label { font-size: 0.72rem; color: var(--text-secondary); }
.empty-state {
    text-align: center;
    padding: 50px 20px;
    color: var(--text-secondary);
}
.empty-state i { font-size: 2.5rem; margin-bottom: 14px; color: var(--border-glow); display: block; }
.empty-state a { color: var(--primary-neon); }

/* ═══════════════════════════════════════════════════════════════
   AUTH PAGES (LOGIN / REGISTER)
═══════════════════════════════════════════════════════════════ */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--header-height) + 20px) 20px 40px;
}
.auth-card {
    background: linear-gradient(145deg, #0c0f1c, #080a14);
    border: 1px solid rgba(0,255,157,0.3);
    border-radius: 24px;
    padding: 44px 40px;
    width: 100%;
    max-width: 440px;
    box-shadow: 0 0 60px rgba(0,255,157,0.1);
    animation: fadeUp 0.6s ease;
}
.auth-icon {
    width: 68px;
    height: 68px;
    background: rgba(0,255,157,0.1);
    border: 1px solid rgba(0,255,157,0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 22px;
    font-size: 1.8rem;
    color: var(--primary-neon);
}
.auth-card h2 {
    text-align: center;
    font-size: 1.4rem;
    margin-bottom: 6px;
}
.auth-card .auth-sub {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 30px;
}
.form-group { margin-bottom: 18px; }
.form-label {
    display: block;
    font-size: 0.72rem;
    font-family: 'Orbitron', monospace;
    color: var(--text-secondary);
    margin-bottom: 8px;
    letter-spacing: 1px;
}
.form-input {
    width: 100%;
    background: rgba(10,14,25,0.9);
    border: 1px solid rgba(0,255,157,0.2);
    border-radius: 10px;
    padding: 11px 14px;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: 'Inter', sans-serif;
    transition: border-color 0.25s;
    -webkit-appearance: none;
}
.form-input:focus {
    outline: none;
    border-color: var(--primary-neon);
    box-shadow: 0 0 0 3px rgba(0,255,157,0.08);
}
.form-input::placeholder { color: rgba(176,176,176,0.4); }
.input-icon-wrap { position: relative; }
.input-icon-wrap .form-input { padding-left: 38px; }
.input-icon-wrap .input-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 0.85rem;
}
.form-submit {
    width: 100%;
    padding: 13px;
    background: transparent;
    border: 2px solid var(--primary-neon);
    border-radius: 10px;
    color: var(--primary-neon);
    font-family: 'Orbitron', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 1px;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 4px;
}
.form-submit:hover {
    background: var(--primary-neon);
    color: var(--primary-bg);
    box-shadow: 0 0 20px rgba(0,255,157,0.4);
}
.auth-footer {
    text-align: center;
    margin-top: 22px;
    font-size: 0.82rem;
    color: var(--text-secondary);
}
.auth-footer a { color: var(--primary-neon); text-decoration: none; }
.auth-footer a:hover { text-decoration: underline; }

/* ═══════════════════════════════════════════════════════════════
   CHALLENGE DETAIL PAGE
═══════════════════════════════════════════════════════════════ */
.challenge-page { padding: calc(var(--header-height) + 28px) 0 60px; }
.chal-detail-header { margin-bottom: 24px; }
.challenge-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0,255,157,0.1);
    border: 1px solid var(--border-glow);
    padding: 4px 14px;
    border-radius: 40px;
    font-size: 0.65rem;
    font-family: 'Orbitron', monospace;
    color: var(--primary-neon);
    margin-bottom: 14px;
}
.challenge-title {
    font-size: clamp(1.6rem, 5.5vw, 2.8rem);
    margin-bottom: 14px;
    line-height: 1.2;
}
.challenge-title .accent { color: var(--primary-neon); text-shadow: 0 0 8px rgba(0,255,157,0.5); }
.challenge-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 24px;
}
.meta-tag {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 6px 14px;
    background: linear-gradient(135deg,rgba(18,22,35,0.9),rgba(10,12,20,0.9));
    border-radius: 30px;
    font-size: 0.68rem;
    font-weight: 500;
    color: var(--text-secondary);
    border: 1px solid rgba(0,255,157,0.2);
    transition: all 0.2s;
}
.meta-tag i { font-size: 0.68rem; color: var(--primary-neon); }
.meta-tag:hover { border-color: var(--primary-neon); transform: translateY(-1px); }
.difficulty-badge { background: linear-gradient(135deg,rgba(0,255,157,0.12),rgba(0,255,157,0.05)); color: var(--primary-neon); border-color: rgba(0,255,157,0.4); }
.points-badge     { background: linear-gradient(135deg,rgba(0,168,255,0.12),rgba(0,168,255,0.05)); border-color: rgba(0,168,255,0.3); }
.points-badge i   { color: var(--secondary-neon); }

/* Collapse sections */
.collapse-section {
    background: var(--card-bg);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-glow);
    border-radius: 20px;
    margin-bottom: 12px;
    overflow: hidden;
}
.collapse-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 20px;
    cursor: pointer;
    transition: background 0.2s;
}
.collapse-header:hover { background: rgba(0,255,157,0.05); }
.collapse-header h3 { font-size: 0.84rem; font-weight: 600; color: var(--text-primary); display: flex; align-items: center; gap: 8px; }
.collapse-header i.toggle-icon { color: var(--primary-neon); transition: transform 0.3s; }
.collapse-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease-out, padding 0.2s;
    padding: 0 20px;
}
.collapse-content.open { max-height: 600px; padding: 0 20px 18px; }
.description-text, .hint-text { color: var(--text-secondary); font-size: 0.85rem; line-height: 1.7; }
.description-text strong { color: var(--text-primary); }
.flag-format-box {
    background: rgba(0,0,0,0.3);
    border: 1px dashed var(--border-glow);
    border-radius: 12px;
    padding: 8px 14px;
    font-family: 'Courier New', monospace;
    font-size: 0.74rem;
    color: var(--primary-neon);
    margin-top: 14px;
}
/* Machine panel */
.machine-panel {
    background: var(--secondary-bg);
    border: 1px solid var(--border-glow);
    border-radius: 20px;
    overflow: hidden;
    margin: 20px 0;
}
.panel-header {
    padding: 12px 18px;
    border-bottom: 1px solid var(--border-glow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}
.panel-title { display: flex; align-items: center; gap: 8px; font-family: 'Orbitron', monospace; font-size: 0.68rem; color: var(--primary-neon); }
.machine-status { display: flex; align-items: center; gap: 8px; }
.status-led { width: 8px; height: 8px; border-radius: 50%; background: var(--danger); box-shadow: 0 0 5px var(--danger); flex-shrink: 0; }
.status-led.active { background: var(--primary-neon); box-shadow: 0 0 8px var(--primary-neon); animation: pulse 1s infinite; }
@keyframes pulse { 0%,100%{ opacity:0.6; transform:scale(0.9); } 50%{ opacity:1; transform:scale(1.2); } }
.status-text { font-size: 0.65rem; color: var(--text-secondary); }
.panel-body { padding: 16px; }
.target-url-box { background: #0a0c14; border-radius: 14px; padding: 12px; margin-bottom: 16px; text-align: center; border: 1px solid #1e2a2a; }
.target-label { font-size: 0.58rem; text-transform: uppercase; letter-spacing: 2px; color: var(--text-secondary); margin-bottom: 8px; }
.url-wrapper { display: flex; align-items: center; justify-content: center; gap: 10px; flex-wrap: wrap; }
.target-url { font-family: 'Courier New', monospace; font-size: 0.78rem; color: var(--primary-neon); word-break: break-all; background: rgba(0,255,157,0.05); padding: 8px 12px; border-radius: 10px; display: inline-block; }
.copy-btn { background: rgba(0,255,157,0.1); border: 1px solid var(--border-glow); color: var(--primary-neon); padding: 6px 12px; border-radius: 8px; font-size: 0.62rem; cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; gap: 5px; font-family: 'Inter', sans-serif; }
.copy-btn:hover { background: var(--primary-neon); color: #0a0a0f; }
.button-group { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn-deploy   { background: linear-gradient(135deg,rgba(0,255,157,0.12),rgba(0,255,157,0.05)); border: 1.5px solid var(--primary-neon); color: var(--primary-neon); padding: 8px 22px; border-radius: 40px; font-family: 'Orbitron', sans-serif; font-weight: 600; font-size: 0.68rem; cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; gap: 8px; }
.btn-deploy:hover { background: var(--primary-neon); color: #0a0a0f; box-shadow: 0 0 12px var(--primary-neon); }
.btn-terminate{ background: linear-gradient(135deg,rgba(255,102,102,0.12),rgba(255,68,68,0.05)); border: 1.5px solid #ff6666; color: #ff6666; padding: 8px 22px; border-radius: 40px; font-family: 'Orbitron', sans-serif; font-weight: 600; font-size: 0.68rem; cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; gap: 8px; }
.btn-terminate:hover { background: #ff6666; color: #0a0a0f; }
/* Flag panel */
.flag-panel { background: var(--secondary-bg); border: 1px solid var(--border-glow); border-radius: 20px; overflow: hidden; margin-bottom: 22px; }
.flag-panel.flag-solved { border-color: rgba(251,191,36,0.4); background: rgba(251,191,36,0.04); }
.flag-input-group { display: flex; gap: 10px; padding: 16px; flex-wrap: wrap; }
.flag-input { flex: 1; min-width: 0; background: #0f111a; border: 1px solid var(--border-glow); padding: 10px 14px; border-radius: 12px; color: #fff; font-family: monospace; font-size: 0.8rem; }
.flag-input:focus { outline: none; border-color: var(--primary-neon); }
.btn-submit { background: var(--primary-neon); border: none; padding: 10px 22px; border-radius: 12px; font-weight: 700; color: #0a0a0f; cursor: pointer; font-family: 'Orbitron', monospace; font-size: 0.72rem; white-space: nowrap; transition: all 0.2s; }
.btn-submit:hover { filter: brightness(1.1); box-shadow: 0 0 10px var(--primary-neon); }
.btn-submit:disabled { opacity: 0.5; cursor: not-allowed; }
.feedback-message { padding: 0 16px 14px; font-size: 0.76rem; color: var(--text-secondary); }
.info-card { background: rgba(15,20,30,0.5); border: 1px solid var(--border-glow); border-radius: 18px; padding: 16px; }
.info-card p { color: var(--text-secondary); font-size: 0.76rem; line-height: 1.6; }
.info-card strong { color: var(--text-primary); }
.info-card code { color: var(--primary-neon); background: rgba(0,255,157,0.1); padding: 2px 5px; border-radius: 4px; font-size: 0.7rem; }
/* Countdown overlay */
.countdown-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.85); backdrop-filter: blur(8px); z-index: 2000; display: flex; align-items: center; justify-content: center; visibility: hidden; opacity: 0; transition: all 0.3s; }
.countdown-overlay.active { visibility: visible; opacity: 1; }
.countdown-number { font-family: 'Orbitron', sans-serif; font-size: 6rem; font-weight: 900; color: var(--primary-neon); text-shadow: 0 0 30px var(--primary-neon); }

/* Back button */
.back-btn { display: inline-flex; align-items: center; gap: 8px; padding: 5px 14px; background: rgba(0,255,157,0.1); border: 1px solid var(--border-glow); border-radius: 40px; color: var(--primary-neon); text-decoration: none; font-size: 0.68rem; font-family: 'Orbitron', monospace; transition: var(--transition); }
.back-btn:hover { background: var(--primary-neon); color: #0a0a0f; }

/* ═══════════════════════════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════════════════════════ */
footer {
    background: var(--secondary-bg);
    padding: 60px 0 28px;
    border-top: 1px solid var(--border-glow);
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}
.footer-links h4 { color: var(--primary-neon); margin-bottom: 14px; font-size: 0.9rem; }
.footer-links ul  { list-style: none; }
.footer-links li  { margin-bottom: 9px; }
.footer-links a   { color: var(--text-secondary); text-decoration: none; transition: var(--transition); font-size: 0.83rem; }
.footer-links a:hover { color: var(--primary-neon); padding-left: 4px; }
.social-icons { display: flex; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
.social-icons a {
    width: 42px; height: 42px;
    background: rgba(255,255,255,0.05);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    transition: var(--transition);
    color: var(--text-secondary);
    font-size: 1.1rem;
    border: 1px solid var(--border-glow);
    text-decoration: none;
}
.social-icons a:hover { background: var(--primary-neon); color: var(--primary-bg); transform: translateY(-3px); border-color: var(--primary-neon); box-shadow: 0 0 12px var(--primary-neon); }
.footer-bottom { text-align: center; padding-top: 28px; border-top: 1px solid rgba(255,255,255,0.05); font-size: 0.78rem; color: var(--text-secondary); }

/* ─── SCROLL TOP ─── */
.scroll-top {
    position: fixed;
    bottom: 28px; right: 28px;
    width: 44px; height: 44px;
    background: var(--primary-neon);
    border: none;
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    cursor: pointer;
    opacity: 0; visibility: hidden;
    transition: var(--transition);
    z-index: 99;
    color: var(--primary-bg);
    font-size: 1rem;
}
.scroll-top.active { opacity: 1; visibility: visible; }
.scroll-top:hover  { transform: translateY(-4px); box-shadow: 0 0 18px var(--primary-neon); }

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE BREAKPOINTS
═══════════════════════════════════════════════════════════════ */

/* Large tablets and small laptops */

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE — COMPLETE MOBILE-FIRST OVERHAUL
   Breakpoints: 1100 · 900 · 768 · 600 · 480 · 380
═══════════════════════════════════════════════════════════════ */

/* ─── 1100px: large tablets / small laptops ─── */
@media (max-width: 1100px) {
    nav ul { gap: 18px; }
    .logo-text { font-size: 1.2rem; }
}

/* ─── 900px: tablets ─── */
@media (max-width: 900px) {
    /* Header: logo | spacer | auth | hamburger — all in one row */
    .header-container {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        gap: 8px;
        height: var(--header-height);
        flex-wrap: nowrap;
    }
    .header-container .logo        { flex-shrink: 0; }
    .header-container nav          { display: none; }   /* hidden; shown as slide-down */
    .header-container .header-auth { flex-shrink: 0; margin-left: auto; }
    .header-container .mobile-menu-btn { flex-shrink: 0; }

    /* Show hamburger */
    .mobile-menu-btn {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    /* Slide-down mobile nav */
    nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: rgba(8, 10, 20, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        padding: 12px 16px 20px;
        transform: translateY(-110%);
        transition: transform 0.32s cubic-bezier(0.2, 0.9, 0.4, 1);
        border-bottom: 1px solid var(--border-glow);
        z-index: 999;
        box-shadow: 0 12px 40px rgba(0,0,0,0.5);
        pointer-events: none;
        visibility: hidden;
    }
    nav.open {
        display: block !important;
        transform: translateY(0);
        pointer-events: auto;
        visibility: visible;
    }
    nav ul {
        flex-direction: column;
        gap: 2px;
        width: 100%;
    }
    nav ul li { width: 100%; }
    nav a {
        display: flex;
        align-items: center;
        gap: 12px;
        padding: 13px 16px;
        border-radius: 10px;
        font-size: 0.92rem;
        width: 100%;
    }
    nav a:hover, nav a.active {
        background: rgba(0,255,157,0.09);
        transform: none;
    }

    /* Hide "Sign In" ghost button, keep Register */
    .header-auth .auth-buttons .btn-ghost { display: none; }

    /* Stats 2 col */
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }

    /* Elite cards fit width */
    .elite-card { width: 300px; padding: 28px 18px; }
    .elite-name  { font-size: 1.35rem; }

    /* Scoreboard: hide less important cols */
    .scoreboard-table .hide-mobile { display: none; }
}

/* ─── 768px: mobile ─── */
@media (max-width: 768px) {
    :root { --header-height: 62px; }

    /* ── Header ── */
    .header-container {
        gap: 6px;
    }
    .logo-img   { height: 36px; }
    .logo-text  { font-size: 1.1rem; }

    /* ── Hero ── */
    .hero { padding-top: calc(var(--header-height) + 16px); min-height: auto; }
    .hero-inner { padding: 40px 0 56px; gap: 32px; }
    .hero h1    { font-size: clamp(1.75rem, 7vw, 2.6rem); }
    .hero p     { font-size: 0.95rem; max-width: 100%; }
    .hero-actions {
        flex-direction: column;
        gap: 12px;
        margin-bottom: 36px;
    }
    .hero-actions .btn {
        width: 100%;
        justify-content: center;
    }

    /* ── Countdown ── */
    .countdown { gap: 10px; justify-content: center; }
    .countdown-card {
        flex: 1;
        min-width: 68px;
        max-width: 90px;
        padding: 14px 8px;
        border-radius: 12px;
    }
    .countdown-num   { font-size: 1.9rem; }
    .countdown-label { font-size: 0.58rem; letter-spacing: 1px; }

    /* ── Stats strip ── */
    .stats-strip { padding: 32px 0; }
    .stats-grid  { grid-template-columns: repeat(2, 1fr); gap: 14px; }
    .stat-icon   { width: 44px; height: 44px; font-size: 1.2rem; border-radius: 12px; }
    .stat-info h3 { font-size: 1.5rem; }

    /* ── Elite cards ── */
    .profiles-elite { padding: 48px 0; }
    .elite-grid {
        gap: 20px;
        justify-content: center;
    }
    .elite-card {
        width: 100%;
        max-width: 340px;
        border-radius: 28px;
        padding: 26px 18px;
    }
    .elite-avatar { width: 110px; height: 110px; }
    .elite-name   { font-size: 1.25rem; }
    .elite-bio    { font-size: 0.82rem; }
    .elite-stats  { font-size: 0.72rem; padding: 8px 12px; gap: 4px; }

    /* ── Section header ── */
    .section-header { margin-bottom: 32px; }
    .section-header h2 { font-size: clamp(1.4rem, 5vw, 2rem); }

    /* ── Categories ── */
    .categories-grid { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }

    /* ── Challenges ── */
    .challenges-grid { grid-template-columns: 1fr; gap: 14px; }

    /* ── CTA banner ── */
    .cta-banner { padding: 48px 0; }
    .cta-actions {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }
    .cta-actions .btn { width: 100%; justify-content: center; }

    /* ── Auth pages ── */
    .auth-page  { padding: calc(var(--header-height) + 16px) 16px 32px; }
    .auth-card  { padding: 32px 22px; border-radius: 20px; max-width: 100%; }
    .auth-card h2 { font-size: 1.25rem; }

    /* ── Profile ── */
    .profile-header  { flex-direction: column; align-items: flex-start; gap: 16px; }
    .profile-avatar  { width: 76px; height: 76px; font-size: 2rem; }
    .profile-info h2 { font-size: 1.5rem; }
    .stats-cards     { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .stat-card .num  { font-size: 1.7rem; }

    /* ── Challenge detail ── */
    .challenge-page { padding: calc(var(--header-height) + 16px) 0 48px; }
    .challenge-title { font-size: clamp(1.4rem, 6vw, 2.2rem); }
    .challenge-layout {
        display: flex !important;
        flex-direction: column !important;
        gap: 16px !important;
    }
    .challenge-layout > * { width: 100% !important; }
    .flag-input-group { flex-direction: column; gap: 10px; }
    .btn-submit       { width: 100%; justify-content: center; }
    .url-wrapper      { flex-direction: column; align-items: stretch; gap: 8px; }
    .copy-btn         { text-align: center; justify-content: center; }
    .button-group     { flex-wrap: wrap; }
    .button-group > * { flex: 1; min-width: 130px; justify-content: center; }
    .panel-header     { flex-wrap: wrap; gap: 8px; }
    .countdown-overlay .countdown-number { font-size: 4rem; }

    /* ── Scoreboard ── */
    .scoreboard-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border-radius: 16px; }
    .scoreboard-table      { min-width: 380px; }
    .scoreboard-table th,
    .scoreboard-table td   { padding: 11px 12px; font-size: 0.8rem; }
    .my-rank-banner        { flex-direction: column; align-items: flex-start; gap: 8px; }

    /* ── Footer ── */
    footer { padding: 44px 0 24px; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }

    /* ── Scroll top ── */
    .scroll-top { bottom: 20px; right: 16px; width: 40px; height: 40px; }
}

/* ─── 600px: small phones ─── */
@media (max-width: 600px) {
    /* ── Header tight ── */
    .header-container {
        gap: 4px;
    }
    .user-pill { padding: 5px 10px 5px 8px; gap: 6px; }
    .user-pill-name { max-width: 72px; font-size: 0.58rem; }
    .user-pill-pts  { display: none; }

    /* Show only Register button */
    .auth-buttons .btn-ghost { display: none; }
    .auth-buttons .btn-sm { padding: 7px 14px; font-size: 0.7rem; }

    /* ── Hero ── */
    .hero-inner { padding: 32px 0 48px; }
    .hero-badge { font-size: 0.65rem; padding: 5px 14px; }

    /* ── Stats ── */
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .stat-icon  { width: 40px; height: 40px; font-size: 1.1rem; border-radius: 10px; }
    .stat-info h3 { font-size: 1.3rem; }
    .stat-info p  { font-size: 0.72rem; }

    /* ── Categories 1-col ── */
    .categories-grid { grid-template-columns: 1fr; }

    /* ── Footer collapse ── */
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .footer-grid > div:first-child {
        border-bottom: 1px solid rgba(255,255,255,0.06);
        padding-bottom: 20px;
    }
    .footer-links ul { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; }
    .footer-links li { margin-bottom: 0; }

    /* ── Auth card ── */
    .btn-google-auth { font-size: 0.85rem; padding: 12px 14px; gap: 10px; }
    .auth-card { padding: 28px 16px; }
    .auth-icon { width: 56px; height: 56px; font-size: 1.5rem; }

    /* ── Profile ── */
    .profile-hero { padding: 32px 0 28px; }
    .meta-pill    { font-size: 0.66rem; padding: 4px 10px; }
    .solved-item  { padding: 12px 14px; gap: 10px; }

    /* ── Scoreboard ── */
    .my-rank-banner .rank-num { font-size: 1.5rem; }
    .page-section { padding: 40px 0; }
}

/* ─── 480px: very small phones ─── */
@media (max-width: 480px) {
    :root { --header-height: 58px; }

    .logo-img  { height: 32px; }
    .logo-text { font-size: 1rem; }
    .mobile-menu-btn { padding: 7px 9px; font-size: 1rem; }
    .header-container { gap: 4px; }

    /* ── Hero ── */
    .hero h1 { font-size: clamp(1.6rem, 8vw, 2.1rem); line-height: 1.15; }
    .hero p  { font-size: 0.9rem; }
    .hero-badge { font-size: 0.6rem; padding: 5px 12px; gap: 7px; }

    /* Countdown tighter */
    .countdown { gap: 8px; }
    .countdown-card  { min-width: 60px; padding: 12px 6px; border-radius: 10px; }
    .countdown-num   { font-size: 1.65rem; }
    .countdown-label { font-size: 0.52rem; letter-spacing: 0.5px; }

    /* ── Stats single col ── */
    .stats-grid { grid-template-columns: 1fr; gap: 12px; }
    .stat-item  { gap: 12px; }
    .stat-icon  { width: 44px; height: 44px; }
    .stat-info h3 { font-size: 1.5rem; }

    /* ── Elite ── */
    .elite-card   { max-width: 100%; border-radius: 22px; padding: 22px 14px; }
    .elite-avatar { width: 100px; height: 100px; }
    .elite-name   { font-size: 1.15rem; }

    /* ── Auth ── */
    .auth-card  { padding: 24px 14px; border-radius: 18px; }
    .auth-card h2 { font-size: 1.15rem; }
    .auth-sub   { font-size: 0.8rem; }
    .form-input { font-size: 0.85rem; padding: 10px 12px; }
    .input-icon-wrap .form-input { padding-left: 36px; }
    .form-submit { font-size: 0.75rem; padding: 12px; }
    .auth-footer { font-size: 0.78rem; }

    /* ── Profile ── */
    .stats-cards { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .stat-card   { padding: 16px 12px; }
    .stat-card .num { font-size: 1.5rem; }
    .stat-card .lbl { font-size: 0.66rem; }

    /* ── Scoreboard ── */
    .scoreboard-table { min-width: 320px; }
    .scoreboard-table th,
    .scoreboard-table td { padding: 9px 8px; font-size: 0.75rem; }
    .rank-cell { font-size: 0.9rem; }

    /* ── Challenge detail ── */
    .challenge-title { font-size: clamp(1.3rem, 7vw, 1.8rem); }
    .meta-tag        { font-size: 0.62rem; padding: 5px 10px; }
    .collapse-header { padding: 12px 14px; }
    .collapse-header h3 { font-size: 0.78rem; }
    .flag-input      { font-size: 0.75rem; padding: 9px 12px; }
    .btn-submit      { font-size: 0.7rem; padding: 9px 16px; }

    /* ── Sections ── */
    .profiles-elite,
    .categories-section { padding: 40px 0; }
    .cta-banner   { padding: 40px 0; }
    .section-tag  { font-size: 0.62rem; padding: 4px 12px; }

    /* ── Footer ── */
    footer { padding: 36px 0 20px; }
    .footer-grid { gap: 20px; }
    .social-icons a { width: 38px; height: 38px; font-size: 1rem; }
    .footer-bottom { font-size: 0.72rem; }

    /* ── Scroll top ── */
    .scroll-top { width: 38px; height: 38px; font-size: 0.85rem; bottom: 16px; right: 12px; }
}

/* ─── 380px: ultra-small (Galaxy S8, iPhone SE) ─── */
@media (max-width: 380px) {
    :root { --header-height: 55px; }

    .logo-text { font-size: 0.92rem; }
    .logo-img  { height: 28px; }
    .header-container { gap: 2px; }

    .container { padding: 0 12px; }

    .hero h1 { font-size: 1.5rem; }
    .hero-actions .btn { font-size: 0.75rem; padding: 10px 16px; }

    .countdown-card { min-width: 54px; padding: 10px 4px; }
    .countdown-num  { font-size: 1.5rem; }

    .stats-grid { grid-template-columns: 1fr; }

    .elite-avatar { width: 88px; height: 88px; }
    .elite-stats  { flex-direction: column; align-items: center; gap: 4px; font-size: 0.7rem; }

    .auth-card { padding: 20px 12px; }
    .btn-google-auth { font-size: 0.8rem; padding: 11px 10px; }

    /* Keep both auth buttons but smaller */
    .auth-buttons { gap: 6px; }
    .auth-buttons .btn-sm { padding: 6px 10px; font-size: 0.64rem; }

    .scoreboard-table { min-width: 290px; }
}

/* ═══════════════════════════════════════════════════════════════
   FIREBASE / GOOGLE AUTH BUTTON
═══════════════════════════════════════════════════════════════ */
.btn-google-auth {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 13px 18px;
    background: #fff;
    border: none;
    border-radius: 10px;
    color: #3c4043;
    font-family: 'Inter', sans-serif;
    font-size: 0.92rem;
    font-weight: 600;
    cursor: pointer;
    transition: box-shadow 0.2s, transform 0.15s;
    box-shadow: 0 1px 4px rgba(0,0,0,0.3);
    margin-bottom: 4px;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}
.btn-google-auth:hover  { box-shadow: 0 4px 16px rgba(0,0,0,0.4); transform: translateY(-1px); }
.btn-google-auth:active { transform: scale(0.98); }
.btn-google-auth:disabled { opacity: 0.7; cursor: not-allowed; transform: none; }
.btn-google-auth img { width: 22px; height: 22px; display: inline-block; flex-shrink: 0; }

/* Auth divider */
.auth-divider {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 20px 0;
    color: var(--text-secondary);
    font-size: 0.75rem;
}
.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(255,255,255,0.08);
}

/* Google auth inline error */
.google-auth-error {
    text-align: center;
    color: #ff6666;
    font-size: 0.78rem;
    margin-top: 8px;
    animation: fadeUp 0.3s ease;
}