/* ============================================
   onlyMATHs — Premium Design System
   ============================================ */

/* ── CSS Custom Properties ──────────────────── */
:root {
    /* Base palette */
    --bg-primary:    #0a0e1a;
    --bg-secondary:  #111827;
    --bg-card:       rgba(17, 24, 39, .7);
    --bg-card-hover: rgba(30, 41, 59, .8);
    --bg-surface:    #1e293b;
    --bg-elevated:   #1e293b;

    /* Text */
    --text-primary:   #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted:     #64748b;
    --text-on-accent: #ffffff;

    /* Accents */
    --accent:         #6C63FF;
    --accent-hover:   #7c74ff;
    --accent-glow:    rgba(108, 99, 255, .35);
    --cyan:           #22d3ee;
    --cyan-glow:      rgba(34, 211, 238, .25);
    --emerald:        #34d399;
    --amber:          #fbbf24;
    --rose:           #fb7185;
    --purple:         #a78bfa;

    /* Gradients */
    --gradient-accent: linear-gradient(135deg, #6C63FF 0%, #22d3ee 100%);
    --gradient-card:   linear-gradient(145deg, rgba(30,41,59,.5) 0%, rgba(17,24,39,.8) 100%);
    --gradient-hero:   radial-gradient(ellipse at 30% 0%, rgba(108,99,255,.15) 0%, transparent 60%),
                       radial-gradient(ellipse at 80% 100%, rgba(34,211,238,.1) 0%, transparent 50%);

    /* Effects */
    --glass:           rgba(15, 23, 42, .6);
    --glass-border:    rgba(148, 163, 184, .08);
    --shadow-sm:       0 2px 8px rgba(0,0,0,.25);
    --shadow-md:       0 8px 30px rgba(0,0,0,.35);
    --shadow-lg:       0 20px 60px rgba(0,0,0,.4);
    --shadow-glow:     0 0 40px var(--accent-glow);
    --border-radius:   14px;
    --border-radius-sm: 8px;
    --border-radius-lg: 20px;

    /* Typography */
    --font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono:  'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --section-gap: 120px;
    --container-width: 1200px;

    /* Transitions */
    --ease-out:  cubic-bezier(.16, 1, .3, 1);
    --ease-spring: cubic-bezier(.34, 1.56, .64, 1);
    --duration:  .35s;
}

/* ── Reset & Base ───────────────────────────── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

a { color: inherit; text-decoration: none; transition: color var(--duration) var(--ease-out); }
img { max-width: 100%; display: block; }
button { cursor: pointer; font: inherit; border: none; background: none; }
ul { list-style: none; }

.container {
    width: min(var(--container-width), 92%);
    margin: 0 auto;
}

/* ── Animated Background ────────────────────── */
.bg-grid {
    position: fixed;
    inset: 0;
    z-index: -2;
    background-image:
        linear-gradient(rgba(148,163,184,.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(148,163,184,.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at 50% 50%, black 30%, transparent 70%);
}

.bg-glow {
    position: fixed;
    z-index: -1;
    border-radius: 50%;
    filter: blur(120px);
    pointer-events: none;
    animation: glowDrift 15s ease-in-out infinite alternate;
}
.bg-glow--1 {
    width: 600px; height: 600px;
    top: -200px; left: -100px;
    background: var(--accent-glow);
}
.bg-glow--2 {
    width: 500px; height: 500px;
    bottom: -150px; right: -100px;
    background: var(--cyan-glow);
    animation-delay: -7s;
}

@keyframes glowDrift {
    0%   { transform: translate(0, 0) scale(1); }
    100% { transform: translate(40px, 30px) scale(1.1); }
}

/* ── Navigation ─────────────────────────────── */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    padding: 0 0;
    transition: background var(--duration) var(--ease-out),
                box-shadow var(--duration) var(--ease-out),
                backdrop-filter var(--duration) var(--ease-out);
}
.nav.scrolled {
    background: rgba(10, 14, 26, .85);
    backdrop-filter: blur(20px) saturate(1.2);
    -webkit-backdrop-filter: blur(20px) saturate(1.2);
    box-shadow: 0 1px 0 var(--glass-border), var(--shadow-sm);
}

.nav__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav__brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -.02em;
}
.nav__logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px; height: 38px;
    border-radius: 10px;
    background: var(--gradient-accent);
    font-size: 1.3rem;
    font-weight: 800;
    color: #fff;
    box-shadow: 0 0 20px var(--accent-glow);
}
.nav__name strong { color: var(--accent); }

.nav__links {
    display: flex;
    align-items: center;
    gap: 8px;
}
.nav__links a {
    padding: 8px 16px;
    border-radius: var(--border-radius-sm);
    font-size: .9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--duration), background var(--duration);
}
.nav__links a:hover,
.nav__links a.active {
    color: var(--text-primary);
    background: rgba(148, 163, 184, .08);
}
.nav__link--subtle { opacity: .6; }
.nav__link--subtle:hover { opacity: 1; }

.nav__user {
    display: flex; align-items: center; gap: 8px;
    padding: 4px 12px 4px 4px;
    border-radius: 30px;
    background: var(--bg-surface);
}
.nav__avatar {
    width: 30px; height: 30px;
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: .75rem; font-weight: 700; color: #fff;
}
.nav__username { font-size: .85rem; font-weight: 500; }

.nav__toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 28px;
    padding: 4px 0;
}
.nav__toggle span {
    display: block; height: 2px;
    background: var(--text-secondary);
    border-radius: 2px;
    transition: transform .3s, opacity .3s;
}

.nav__cta {
    background: var(--gradient-accent) !important;
    color: #fff !important;
    font-weight: 600 !important;
}

/* ── Buttons ────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -.01em;
    transition: transform var(--duration) var(--ease-spring),
                box-shadow var(--duration) var(--ease-out),
                background var(--duration);
    position: relative;
    overflow: hidden;
}
.btn::before {
    content: '';
    position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,.1) 0%, transparent 50%);
    opacity: 0;
    transition: opacity var(--duration);
}
.btn:hover::before { opacity: 1; }
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0) scale(.98); }

.btn--primary {
    background: var(--gradient-accent);
    color: #fff;
    box-shadow: 0 4px 20px var(--accent-glow);
}
.btn--primary:hover { box-shadow: 0 8px 40px var(--accent-glow); }

.btn--secondary {
    background: var(--bg-surface);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}
.btn--secondary:hover {
    background: var(--bg-card-hover);
    border-color: rgba(148, 163, 184, .15);
}

.btn--sm { padding: 8px 20px; font-size: .85rem; border-radius: var(--border-radius-sm); }
.btn--lg { padding: 18px 42px; font-size: 1.1rem; }

.btn--accent {
    background: var(--gradient-accent);
    color: #fff;
}

.btn--ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--glass-border);
}
.btn--ghost:hover {
    color: var(--text-primary);
    border-color: var(--accent);
    background: rgba(108, 99, 255, .08);
}

/* ── Section Styles ─────────────────────────── */
.section {
    padding: var(--section-gap) 0;
    position: relative;
}
.section__label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    border-radius: 30px;
    background: rgba(108, 99, 255, .1);
    border: 1px solid rgba(108, 99, 255, .2);
    color: var(--accent);
    font-size: .8rem;
    font-weight: 600;
    letter-spacing: .05em;
    text-transform: uppercase;
    margin-bottom: 20px;
}
.section__title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    letter-spacing: -.03em;
    line-height: 1.15;
    margin-bottom: 16px;
}
.section__subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    line-height: 1.7;
}
.section__header {
    text-align: center;
    margin-bottom: 60px;
}
.section__header .section__subtitle { margin: 0 auto; }

/* ── Hero Section ───────────────────────────── */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 72px;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
    pointer-events: none;
}

.hero__inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero__content { max-width: 580px; }
.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: 30px;
    background: rgba(108, 99, 255, .12);
    border: 1px solid rgba(108, 99, 255, .25);
    color: var(--accent);
    font-size: .82rem;
    font-weight: 600;
    margin-bottom: 28px;
    animation: fadeInUp .8s var(--ease-out) both;
}
.hero__badge::before {
    content: '';
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--emerald);
    box-shadow: 0 0 8px var(--emerald);
    animation: pulse 2s ease-in-out infinite;
}

.hero__title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 900;
    letter-spacing: -.04em;
    line-height: 1.08;
    margin-bottom: 24px;
    animation: fadeInUp .8s .1s var(--ease-out) both;
}
.hero__title span {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero__desc {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin-bottom: 40px;
    animation: fadeInUp .8s .2s var(--ease-out) both;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 56px;
    animation: fadeInUp .8s .3s var(--ease-out) both;
}

.hero__stats {
    display: flex;
    gap: 48px;
    animation: fadeInUp .8s .4s var(--ease-out) both;
}
.hero__stat { text-align: left; }
.hero__stat-value {
    font-family: var(--font-mono);
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -.02em;
}
.hero__stat-value span { color: var(--accent); }
.hero__stat-label {
    font-size: .82rem;
    color: var(--text-muted);
    margin-top: 2px;
}

/* Hero visual (right side) */
.hero__visual {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeInUp .8s .3s var(--ease-out) both;
}

.hero__card-stack {
    position: relative;
    width: 100%;
    max-width: 420px;
    aspect-ratio: 1;
}

.hero__float-card {
    position: absolute;
    background: var(--glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    padding: 20px 24px;
    box-shadow: var(--shadow-md);
    animation: floatCard 6s ease-in-out infinite;
}
.hero__float-card:nth-child(1) {
    top: 10%; left: 5%;
    background: linear-gradient(135deg, rgba(108,99,255,.15) 0%, var(--glass) 100%);
    animation-delay: 0s;
}
.hero__float-card:nth-child(2) {
    top: 35%; right: 0;
    background: linear-gradient(135deg, rgba(34,211,238,.12) 0%, var(--glass) 100%);
    animation-delay: -2s;
}
.hero__float-card:nth-child(3) {
    bottom: 15%; left: 15%;
    background: linear-gradient(135deg, rgba(52,211,153,.12) 0%, var(--glass) 100%);
    animation-delay: -4s;
}

.hero__float-card .card__emoji { font-size: 1.6rem; margin-bottom: 8px; }
.hero__float-card .card__q {
    font-family: var(--font-mono);
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 4px;
}
.hero__float-card .card__label {
    font-size: .75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: .05em;
}
.hero__float-card .card__score {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--emerald);
}

@keyframes floatCard {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-14px); }
}

/* ── Game Mode Cards ────────────────────────── */
.games-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.game-card {
    position: relative;
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    padding: 32px 28px 28px;
    transition: transform var(--duration) var(--ease-spring),
                box-shadow var(--duration) var(--ease-out),
                border-color var(--duration);
    cursor: pointer;
    overflow: hidden;
}
.game-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--gradient-accent);
    opacity: 0;
    transition: opacity var(--duration);
}
.game-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg), 0 0 50px var(--accent-glow);
    border-color: rgba(108, 99, 255, .2);
}
.game-card:hover::before { opacity: 1; }

.game-card__icon {
    font-size: 2.2rem;
    margin-bottom: 18px;
    display: inline-block;
    transition: transform var(--duration) var(--ease-spring);
}
.game-card:hover .game-card__icon { transform: scale(1.15) rotate(-5deg); }

.game-card__title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -.01em;
}
.game-card__desc {
    font-size: .88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

.game-card__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.game-card__badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: .72rem;
    font-weight: 600;
    letter-spacing: .03em;
    text-transform: uppercase;
}
.game-card__badge--easy    { background: rgba(52,211,153,.12); color: var(--emerald); }
.game-card__badge--medium  { background: rgba(251,191,36,.12); color: var(--amber); }
.game-card__badge--hard    { background: rgba(251,113,133,.12); color: var(--rose); }
.game-card__badge--pro     { background: rgba(167,139,250,.12); color: var(--purple); }

.game-card__play {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    border-radius: var(--border-radius-sm);
    background: var(--gradient-accent);
    color: #fff;
    font-size: .82rem;
    font-weight: 600;
    transition: transform var(--duration) var(--ease-spring), box-shadow var(--duration);
    box-shadow: 0 2px 10px var(--accent-glow);
}
.game-card__play:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 20px var(--accent-glow);
}
.game-card__play svg { width: 14px; height: 14px; }

.game-card__duration {
    font-size: .75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* ── Leaderboard ────────────────────────────── */
.leaderboard {
    max-width: 700px;
    margin: 0 auto;
}

.leaderboard__tabs {
    display: flex;
    gap: 4px;
    background: var(--bg-surface);
    border-radius: var(--border-radius);
    padding: 4px;
    margin-bottom: 32px;
    max-width: 300px;
    margin-left: auto;
    margin-right: auto;
}
.leaderboard__tab {
    flex: 1;
    padding: 10px 20px;
    border-radius: 10px;
    font-size: .88rem;
    font-weight: 600;
    color: var(--text-muted);
    text-align: center;
    transition: background var(--duration), color var(--duration);
}
.leaderboard__tab.active {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 2px 12px var(--accent-glow);
}
.leaderboard__tab:hover:not(.active) { color: var(--text-primary); }

.lb-list { display: flex; flex-direction: column; gap: 10px; }

.lb-row {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    transition: transform var(--duration) var(--ease-out), background var(--duration);
    animation: fadeInUp .5s var(--ease-out) both;
}
.lb-row:hover {
    transform: translateX(4px);
    background: var(--bg-card-hover);
}
.lb-row:nth-child(1) { animation-delay: 0s;   border-color: rgba(251,191,36,.25); }
.lb-row:nth-child(2) { animation-delay: .05s;  border-color: rgba(148,163,184,.2); }
.lb-row:nth-child(3) { animation-delay: .1s;   border-color: rgba(205,127,50,.25); }

.lb-rank {
    width: 36px; height: 36px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 10px;
    font-family: var(--font-mono);
    font-size: .9rem;
    font-weight: 700;
    background: var(--bg-surface);
    flex-shrink: 0;
}
.lb-row:nth-child(1) .lb-rank { background: linear-gradient(135deg, #fbbf24, #f59e0b); color: #1a1a2e; }
.lb-row:nth-child(2) .lb-rank { background: linear-gradient(135deg, #94a3b8, #cbd5e1); color: #1a1a2e; }
.lb-row:nth-child(3) .lb-rank { background: linear-gradient(135deg, #cd7f32, #b8860b); color: #1a1a2e; }

.lb-avatar {
    width: 38px; height: 38px;
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: .82rem; font-weight: 700; color: #fff;
    flex-shrink: 0;
}
.lb-info { flex: 1; min-width: 0; }
.lb-name {
    font-weight: 600;
    font-size: .95rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.lb-games {
    font-size: .75rem;
    color: var(--text-muted);
}
.lb-score {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent);
    flex-shrink: 0;
}
.lb-streak {
    font-size: .75rem;
    color: var(--emerald);
    font-weight: 600;
    flex-shrink: 0;
}

/* ── High Scores Panel ──────────────────────── */
.scores-panel {
    max-width: 700px;
    margin: 0 auto;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    padding: 40px;
}
.scores-panel__empty {
    text-align: center;
    padding: 40px 20px;
}
.scores-panel__empty-icon { font-size: 3rem; margin-bottom: 16px; }
.scores-panel__empty h3 {
    font-size: 1.3rem;
    margin-bottom: 8px;
}
.scores-panel__empty p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

/* ── How It Works ───────────────────────────── */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 32px;
    counter-reset: step;
}
.step-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    padding: 36px 28px;
    text-align: center;
    counter-increment: step;
    transition: transform var(--duration) var(--ease-spring), box-shadow var(--duration);
}
.step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}
.step-card__number {
    width: 48px; height: 48px;
    margin: 0 auto 20px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 14px;
    background: var(--gradient-accent);
    font-family: var(--font-mono);
    font-size: 1.2rem;
    font-weight: 800;
    color: #fff;
    box-shadow: 0 4px 16px var(--accent-glow);
}
.step-card__title {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 8px;
}
.step-card__desc {
    font-size: .88rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* ── Benefits / Why Play ────────────────────── */
.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}
.benefit-card {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    transition: transform var(--duration) var(--ease-spring), background var(--duration);
}
.benefit-card:hover {
    transform: translateY(-3px);
    background: var(--bg-card-hover);
}
.benefit-card__icon {
    width: 52px; height: 52px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 14px;
    font-size: 1.5rem;
    flex-shrink: 0;
}
.benefit-card__icon--blue   { background: rgba(108,99,255,.12); }
.benefit-card__icon--cyan   { background: rgba(34,211,238,.12); }
.benefit-card__icon--green  { background: rgba(52,211,153,.12); }
.benefit-card__icon--amber  { background: rgba(251,191,36,.12); }
.benefit-card__icon--rose   { background: rgba(251,113,133,.12); }
.benefit-card__icon--purple { background: rgba(167,139,250,.12); }

.benefit-card__title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 6px;
}
.benefit-card__desc {
    font-size: .85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ── CTA Banner ─────────────────────────────── */
.cta-banner {
    text-align: center;
    padding: 80px 40px;
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    position: relative;
    overflow: hidden;
}
.cta-banner::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 50% 0%, rgba(108,99,255,.15) 0%, transparent 60%);
    pointer-events: none;
}
.cta-banner__title {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 800;
    letter-spacing: -.03em;
    margin-bottom: 16px;
    position: relative;
}
.cta-banner__desc {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto 32px;
    position: relative;
}

/* ── Footer ─────────────────────────────────── */
.footer {
    padding: 80px 0 40px;
    border-top: 1px solid var(--glass-border);
    margin-top: var(--section-gap);
}
.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}
.footer__tagline {
    color: var(--text-muted);
    font-size: .9rem;
    margin-top: 16px;
    line-height: 1.6;
}
.footer__heading {
    font-size: .8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .06em;
    color: var(--text-muted);
    margin-bottom: 16px;
}
.footer__col ul { display: flex; flex-direction: column; gap: 10px; }
.footer__col a {
    font-size: .88rem;
    color: var(--text-secondary);
    transition: color var(--duration);
}
.footer__col a:hover { color: var(--text-primary); }

.footer__bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 32px;
    border-top: 1px solid var(--glass-border);
    font-size: .82rem;
    color: var(--text-muted);
}
.footer__social {
    display: flex;
    gap: 16px;
}
.footer__social-link {
    color: var(--text-muted);
    transition: color var(--duration), transform var(--duration) var(--ease-spring);
}
.footer__social-link:hover {
    color: var(--accent);
    transform: translateY(-2px);
}

/* ── Form Styles ────────────────────────────── */
.form-card {
    max-width: 440px;
    margin: 0 auto;
    padding: 48px 40px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
}
.form-card__title {
    font-size: 1.6rem;
    font-weight: 800;
    margin-bottom: 8px;
    text-align: center;
}
.form-card__subtitle {
    font-size: .9rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 32px;
}

.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    font-size: .85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
}
.form-group input {
    width: 100%;
    padding: 14px 18px;
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    font-size: .95rem;
    transition: border-color var(--duration), box-shadow var(--duration);
    outline: none;
}
.form-group input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}
.form-group input::placeholder { color: var(--text-muted); }

.form-error {
    background: rgba(251, 113, 133, .1);
    border: 1px solid rgba(251, 113, 133, .2);
    color: var(--rose);
    padding: 12px 16px;
    border-radius: var(--border-radius-sm);
    font-size: .85rem;
    margin-bottom: 20px;
}
.form-success {
    background: rgba(52, 211, 153, .1);
    border: 1px solid rgba(52, 211, 153, .2);
    color: var(--emerald);
    padding: 12px 16px;
    border-radius: var(--border-radius-sm);
    font-size: .85rem;
    margin-bottom: 20px;
}

.form-footer {
    text-align: center;
    margin-top: 24px;
    font-size: .85rem;
    color: var(--text-muted);
}
.form-footer a { color: var(--accent); font-weight: 600; }
.form-footer a:hover { text-decoration: underline; }

/* ── Animations ─────────────────────────────── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}
@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50%      { opacity: .5; transform: scale(1.2); }
}
@keyframes slideUp {
    from { opacity: 0; transform: translateY(40px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* Reveal-on-scroll */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ── Difficulty selector (game page) ─────────── */
.difficulty-selector {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}
.difficulty-btn {
    padding: 10px 24px;
    border-radius: var(--border-radius-sm);
    font-size: .85rem;
    font-weight: 600;
    border: 1px solid var(--glass-border);
    background: var(--bg-surface);
    color: var(--text-secondary);
    transition: all var(--duration);
}
.difficulty-btn.active,
.difficulty-btn:hover {
    border-color: var(--accent);
    color: var(--text-primary);
    background: rgba(108, 99, 255, .1);
}
.difficulty-btn.active {
    background: var(--accent);
    color: #fff;
}

/* ── Utility ────────────────────────────────── */
.text-center { text-align: center; }
.text-accent { color: var(--accent); }
.mt-4 { margin-top: 32px; }
.mb-4 { margin-bottom: 32px; }
.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}

/* Auth page layout */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 100px 20px 60px;
}

/* Leaderboard page specific */
.leaderboard-page {
    padding-top: 120px;
}

/* ══════════════════════════════════════════════
   PROFILE PAGE
══════════════════════════════════════════════ */
.profile-page {
    padding-top: 120px;
    padding-bottom: 80px;
}

/* ── Hero Card ─────────────────────────────── */
.profile-hero {
    display: flex;
    align-items: center;
    gap: 28px;
    background: rgba(255,255,255,.04);
    border: 1px solid rgba(255,255,255,.08);
    border-radius: 24px;
    padding: 36px 40px;
    margin-bottom: 32px;
    position: relative;
    overflow: hidden;
}
.profile-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 0% 0%, rgba(108,99,255,.12) 0%, transparent 60%);
    pointer-events: none;
}

.profile-hero__avatar {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--avatar-color, #6C63FF);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-mono);
    font-size: 1.6rem;
    font-weight: 800;
    color: #fff;
    box-shadow: 0 0 0 4px rgba(255,255,255,.08),
                0 0 24px color-mix(in srgb, var(--avatar-color, #6C63FF) 40%, transparent);
}

.profile-hero__info {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.profile-hero__name {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -.02em;
    line-height: 1.1;
    margin: 0;
}
.profile-hero__handle {
    font-size: .85rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* ── Stat Cards ────────────────────────────── */
.profile-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 40px;
}

.pstat {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 24px 20px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.07);
    border-radius: 20px;
    transition: transform .2s var(--ease-spring), box-shadow .2s;
    position: relative;
    overflow: hidden;
}
.pstat::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 2px;
    border-radius: 0 0 20px 20px;
    opacity: .7;
}
.pstat:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 40px rgba(0,0,0,.3);
}

.pstat--score::after  { background: var(--accent); }
.pstat--games::after  { background: var(--cyan); }
.pstat--streak::after { background: var(--amber); }
.pstat--avg::after    { background: var(--emerald); }

.pstat__icon {
    font-size: 2rem;
    line-height: 1;
    flex-shrink: 0;
}

.pstat__value {
    font-family: var(--font-mono);
    font-size: 1.8rem;
    font-weight: 800;
    line-height: 1;
}
.pstat__label {
    font-size: .7rem;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--text-muted);
    margin-top: 5px;
}

.pstat--score  .pstat__value { color: var(--accent); }
.pstat--games  .pstat__value { color: var(--cyan); }
.pstat--streak .pstat__value { color: var(--amber); }
.pstat--avg    .pstat__value { color: var(--emerald); }

/* ── Recent Scores Panel ───────────────────── */
.profile-scores {
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.07);
    border-radius: 24px;
    padding: 32px;
}

.profile-scores__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}
.profile-scores__title {
    font-size: 1.15rem;
    font-weight: 700;
    margin: 0;
}

.score-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.score-row {
    display: grid;
    grid-template-columns: 36px 1fr auto auto;
    align-items: center;
    gap: 16px;
    padding: 14px 18px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.06);
    border-radius: 14px;
    transition: background .15s;
}
.score-row:hover { background: rgba(255,255,255,.06); }

.score-row__rank {
    font-family: var(--font-mono);
    font-size: .75rem;
    font-weight: 700;
    color: var(--text-muted);
    text-align: center;
    width: 28px;
    height: 28px;
    line-height: 28px;
    background: rgba(255,255,255,.06);
    border-radius: 8px;
}
.score-row:nth-child(1) .score-row__rank { background: rgba(251,191,36,.15); color: var(--amber); }
.score-row:nth-child(2) .score-row__rank { background: rgba(148,163,184,.12); color: #94a3b8; }
.score-row:nth-child(3) .score-row__rank { background: rgba(180,120,80,.12);  color: #b47850; }

.score-row__mode {
    display: flex;
    align-items: center;
    gap: 10px;
}
.score-row__icon { font-size: 1.25rem; }
.score-row__name { font-weight: 600; font-size: .9rem; }

.score-row__meta {
    display: flex;
    gap: 10px;
    align-items: center;
}
.score-row__diff {
    font-size: .7rem;
    padding: 3px 8px;
    background: rgba(255,255,255,.06);
    border-radius: 6px;
    color: var(--text-muted);
    font-family: var(--font-mono);
}
.score-row__correct {
    font-size: .75rem;
    color: var(--emerald);
    font-family: var(--font-mono);
}

.score-row__score {
    font-family: var(--font-mono);
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--accent);
    min-width: 60px;
    text-align: right;
}

.profile-scores__empty {
    text-align: center;
    padding: 48px 20px;
    color: var(--text-muted);
}
.profile-scores__empty-icon { font-size: 3rem; margin-bottom: 12px; }

/* ── Responsive ────────────────────────────── */
@media (max-width: 900px) {
    .profile-stats { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
    .profile-hero { flex-direction: column; text-align: center; padding: 28px 20px; }
    .profile-stats { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .pstat { padding: 18px 14px; gap: 12px; }
    .pstat__value { font-size: 1.4rem; }
    .score-row { grid-template-columns: 28px 1fr auto; }
    .score-row__meta { display: none; }
    .profile-scores { padding: 20px 16px; }
}