/* ═══════════════════════════════════════════════════════
   ScrollNice — Premium Design System v2
   ═══════════════════════════════════════════════════════ */
@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,300..900;1,14..32,300..900&family=Space+Grotesk:wght@400;500;600;700&display=swap');

/* ── Variables ── */
:root {
    --bg: #071018;
    --bg-mid: #0d1722;
    --bg-card: rgba(255, 255, 255, 0.04);
    --bg-card-h: rgba(255, 255, 255, 0.08);
    --txt: #f0f0f8;
    --txt2: #90a4bf;
    --accent: #2f80ed;
    --accent2: #25a0d9;
    --accent3: #2cc59f;
    --gold: #f0b24a;
    --grad: linear-gradient(135deg, var(--accent), var(--accent2));
    --grad2: linear-gradient(135deg, var(--accent2), var(--accent3));
    --border: rgba(255, 255, 255, 0.08);
    --border-h: rgba(255, 255, 255, 0.16);
    --r: 18px;
    --shadow-glow: 0 0 50px rgba(59, 130, 246, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    background: var(--bg);
    color: var(--txt);
    line-height: 1.65;
    overflow-x: hidden;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color .2s, opacity .2s;
}

a:hover {
    opacity: .85;
}

strong {
    color: var(--txt);
}

em {
    color: var(--txt2);
    font-style: normal;
    font-size: .93em;
}

small {
    color: var(--txt2);
    font-size: .82em;
}

.container {
    max-width: 1020px;
    margin: 0 auto;
    padding: 0 28px;
}

/* ════════════════════════════════════════════════════════
   KEYFRAME ANIMATIONS
══════════════════════════════════════════════════════════ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(28px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes floatY {

    0%,
    100% {
        transform: translateY(0px);
    }

    50% {
        transform: translateY(-12px);
    }
}

@keyframes glowPulse {

    0%,
    100% {
        box-shadow: 0 0 18px rgba(59, 130, 246, 0.15);
    }

    50% {
        box-shadow: 0 0 36px rgba(139, 92, 246, 0.3);
    }
}

@keyframes shimmer {
    0% {
        background-position: -200% center;
    }

    100% {
        background-position: 200% center;
    }
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

@keyframes rotateGlow {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(.9);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-12px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes blink {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0;
    }
}

@keyframes pulseBorder {

    0%,
    100% {
        border-color: rgba(59, 130, 246, .25);
    }

    50% {
        border-color: rgba(139, 92, 246, .6);
    }
}

@keyframes orbit {
    from {
        transform: rotate(0deg) translateX(70px) rotate(0deg);
    }

    to {
        transform: rotate(360deg) translateX(70px) rotate(-360deg);
    }
}

/* ════════════════════════════════════════════════════════
   SCROLL PROGRESS BAR
══════════════════════════════════════════════════════════ */
#scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 2px;
    width: 0%;
    z-index: 999;
    background: var(--grad);
    transition: width .1s linear;
}

/* ════════════════════════════════════════════════════════
   NAV
══════════════════════════════════════════════════════════ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(8, 8, 16, 0.6);
    backdrop-filter: blur(24px) saturate(1.4);
    border-bottom: 1px solid var(--border);
    transition: background .3s, box-shadow .3s, padding .3s;
}

.nav.scrolled {
    background: rgba(8, 8, 16, 0.92);
    box-shadow: 0 4px 32px rgba(0, 0, 0, .5);
    border-bottom-color: rgba(59, 130, 246, .15);
}

.nav .container {
    display: flex;
    align-items: center;
    gap: 0;
    padding: 16px 28px;
    transition: padding .3s;
}

.nav.scrolled .container {
    padding: 11px 28px;
}

.nav-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-right: auto;
    flex-shrink: 0;
    text-decoration: none;
}

.nav-brand-logo {
    width: 28px;
    height: 28px;
    object-fit: contain;
    flex-shrink: 0;
    border-radius: 6px;
}

.nav-brand-text {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 19px;
    font-weight: 700;
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -.3px;
    white-space: nowrap;
}

.nav-links {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    gap: clamp(12px, 1.4vw, 22px);
    flex-shrink: 0;
}

.nav-links a {
    color: var(--txt2);
    font-size: 13.5px;
    font-weight: 500;
    letter-spacing: .1px;
    position: relative;
    transition: color .2s;
    white-space: nowrap;
    flex-shrink: 0;
}

/* Thanh theme + ngôn ngữ: không co để tránh đẩy menu */
.nav-toolbar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: 16px;
    flex-shrink: 0;
}

/* Trang docs ít link — đẩy theme/lang sang phải */
.nav-toolbar--end {
    margin-left: auto;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    right: 100%;
    height: 1px;
    background: var(--grad);
    transition: right .25s ease;
}

.nav-links a:hover {
    color: var(--txt);
    opacity: 1;
}

.nav-links a:hover::after {
    right: 0;
}

/* Lang toggle */
.lang-toggle {
    display: flex;
    align-items: center;
    gap: 3px;
    margin-left: 20px;
    background: rgba(255, 255, 255, .05);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 3px;
}

.lang-btn {
    padding: 4px 11px;
    border-radius: 7px;
    font-size: 11.5px;
    font-weight: 600;
    color: var(--txt2);
    cursor: pointer;
    background: none;
    border: none;
    transition: all .2s;
    letter-spacing: .3px;
}

.lang-btn:hover {
    color: var(--txt);
}

.lang-btn.active {
    background: var(--grad);
    color: white;
    box-shadow: 0 2px 10px rgba(59, 130, 246, .4);
}

/* Nav CTA */
.nav-cta {
    margin-left: 16px;
    padding: 8px 20px;
    background: var(--grad);
    color: white !important;
    border-radius: 9px;
    font-weight: 600;
    font-size: 13px;
    -webkit-text-fill-color: white;
    transition: transform .2s, box-shadow .2s;
    white-space: nowrap;
}

.nav-cta:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, .35);
}

/* Hamburger (mobile) */
.nav-hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    margin-left: 16px;
    padding: 4px;
    background: none;
    border: none;
}

.nav-hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--txt);
    border-radius: 2px;
    transition: all .3s;
}

.nav-hamburger.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-hamburger.open span:nth-child(2) {
    opacity: 0;
}

.nav-hamburger.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Mobile menu */
.nav-mobile {
    display: none;
    position: fixed;
    top: 57px;
    left: 0;
    right: 0;
    background: rgba(8, 8, 16, .97);
    backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--border);
    padding: 20px 28px;
    flex-direction: column;
    gap: 14px;
    z-index: 99;
    animation: slideDown .22s ease;
}

.nav-mobile.open {
    display: flex;
}

.nav-mobile a {
    color: var(--txt);
    font-weight: 500;
    font-size: 15px;
    white-space: nowrap;
}

/* ════════════════════════════════════════════════════════
   HERO
══════════════════════════════════════════════════════════ */
.hero {
    position: relative;
    padding: 180px 0 120px;
    text-align: center;
    overflow: hidden;
}

/* Enhanced ambient mesh background */
.hero::before {
    content: '';
    position: absolute;
    top: -120px;
    left: 50%;
    transform: translateX(-50%);
    width: 900px;
    height: 700px;
    background: radial-gradient(ellipse at 30% 40%, rgba(59, 130, 246, .15) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 60%, rgba(139, 92, 246, .12) 0%, transparent 60%),
        radial-gradient(ellipse at 50% 80%, rgba(6, 182, 212, .09) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
    animation: gradientShift 8s ease infinite;
}

.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='1' cy='1' r='1' fill='rgba(255,255,255,0.025)'/%3E%3C/svg%3E") repeat;
    pointer-events: none;
    z-index: 0;
}

#hero-canvas {
    position: absolute;
    inset: 0;
    z-index: 0;
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    background: rgba(59, 130, 246, .12);
    border: 1px solid rgba(59, 130, 246, .3);
    border-radius: 24px;
    font-size: 13px;
    color: #60a5fa;
    font-weight: 600;
    margin-bottom: 32px;
    animation: fadeInUp .6s ease both, pulseBorder 3s ease infinite;
    letter-spacing: .4px;
    box-shadow: 0 4px 20px rgba(59, 130, 246, .15);
}

.hero h1 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: clamp(42px, 6vw, 68px);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -1.8px;
    animation: fadeInUp .7s .1s ease both;
}

.hero h1 .gradient {
    background: linear-gradient(135deg, var(--accent), var(--accent2), var(--accent3));
    background-size: 200% 200%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: gradientShift 4s ease infinite;
}

.hero p {
    font-size: 18px;
    color: var(--txt2);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.75;
    animation: fadeInUp .7s .2s ease both;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
    animation: fadeInUp .7s .3s ease both;
}

/* Floating zone demo */
.hero-demo {
    display: flex;
    justify-content: center;
    animation: fadeInUp .8s .4s ease both;
}

.zone-demo {
    position: relative;
    width: 120px;
    height: 180px;
    border-radius: 20px;
    border: 2px solid rgba(255, 255, 255, 0.18);
    background: rgba(59, 130, 246, .15);
    backdrop-filter: blur(12px);
    animation: floatY 4s ease-in-out infinite, glowPulse 4s ease-in-out infinite;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(59, 130, 246, .2), 0 0 60px rgba(59, 130, 246, .1);
}

.zone-demo-top {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    border-bottom: 1px dashed rgba(255, 255, 255, .25);
    transition: background .3s;
}

.zone-demo-bot {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.zone-demo::before {
    content: 'ScrollNice';
    position: absolute;
    bottom: -24px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 10px;
    color: var(--txt2);
    white-space: nowrap;
    letter-spacing: .5px;
}

/* Hero Stats */
.hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
    animation: fadeInUp .7s .45s ease both;
    padding-top: 16px;
    border-top: 1px solid var(--border);
    max-width: 560px;
    margin: 0 auto;
}

.hero-stat {
    text-align: center;
}

.hero-stat strong {
    display: block;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 22px;
    font-weight: 700;
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-stat span {
    font-size: 12px;
    color: var(--txt2);
    letter-spacing: .4px;
    text-transform: uppercase;
}

/* ════════════════════════════════════════════════════════
   BUTTONS
══════════════════════════════════════════════════════════ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 15px;
    transition: all .3s;
    cursor: pointer;
    border: none;
    letter-spacing: .15px;
}

.btn-primary {
    background: var(--grad);
    color: white;
    box-shadow: 0 6px 24px rgba(59, 130, 246, .35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 40px rgba(59, 130, 246, .5);
    opacity: 1;
}

.btn-secondary {
    background: rgba(255, 255, 255, .08);
    color: var(--txt);
    border: 1px solid var(--border-h);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, .12);
    border-color: rgba(59, 130, 246, .4);
    transform: translateY(-3px);
    opacity: 1;
}

/* ════════════════════════════════════════════════════════
   SECTION COMMON
══════════════════════════════════════════════════════════ */
.section-tag {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 10px;
    opacity: .85;
}

section h2 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: clamp(24px, 3.5vw, 36px);
    font-weight: 700;
    text-align: center;
    margin-bottom: 52px;
    letter-spacing: -.5px;
}

.section-head {
    text-align: center;
    margin-bottom: 52px;
}

.section-head p {
    color: var(--txt2);
    font-size: 15px;
    margin-top: 8px;
}

/* ════════════════════════════════════════════════════════
   FEATURES
══════════════════════════════════════════════════════════ */
.roadmap {
    padding: 92px 0 72px;
    background: linear-gradient(180deg, rgba(47, 128, 237, 0.05), rgba(44, 197, 159, 0.03));
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.roadmap-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.roadmap-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 20px;
    transition: transform .2s ease, border-color .2s ease, background .2s ease;
}

.roadmap-card:hover {
    transform: translateY(-4px);
    border-color: rgba(47, 128, 237, .4);
    background: var(--bg-card-h);
}

.roadmap-phase {
    display: inline-flex;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 11px;
    font-weight: 700;
    color: #d7ebff;
    background: linear-gradient(135deg, rgba(47, 128, 237, 0.42), rgba(37, 160, 217, 0.42));
    border: 1px solid rgba(255, 255, 255, 0.18);
    margin-bottom: 12px;
}

.roadmap-card h3 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 20px;
    margin-bottom: 8px;
}

.roadmap-card p {
    color: var(--txt2);
    font-size: 14px;
    line-height: 1.7;
}

.features {
    padding: 90px 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
    gap: 18px;
}

.feature-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: 32px;
    transition: all .35s ease;
    overflow: hidden;
    backdrop-filter: blur(8px);
}

.feature-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--grad);
    opacity: 0;
    transition: opacity .3s;
    border-radius: inherit;
}

.feature-card:hover {
    border-color: rgba(59, 130, 246, .4);
    transform: translateY(-6px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, .5), var(--shadow-glow);
}

.feature-card:hover::before {
    opacity: .05;
}

.feature-num {
    position: absolute;
    top: 20px;
    right: 20px;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 11px;
    font-weight: 700;
    color: var(--txt2);
    opacity: .35;
    letter-spacing: .5px;
}

.feature-icon {
    font-size: 30px;
    margin-bottom: 14px;
    display: block;
}

.feature-card h3 {
    font-size: 15.5px;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 13.5px;
    color: var(--txt2);
    line-height: 1.55;
}

/* ════════════════════════════════════════════════════════
   MODES SECTION
══════════════════════════════════════════════════════════ */
.modes {
    padding: 90px 0;
    background: linear-gradient(180deg, transparent, rgba(255, 255, 255, .018), transparent);
}

.mode-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.mode-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 22px;
    padding: 36px 32px;
    text-align: center;
    transition: all .4s ease;
    overflow: hidden;
    backdrop-filter: blur(12px);
    perspective: 800px;
}

/* Mode glow accents */
.mode-card:nth-child(1) {
    --mc: rgba(59, 130, 246, .6);
    --mcb: rgba(59, 130, 246, .1);
}

.mode-card:nth-child(2) {
    --mc: rgba(139, 92, 246, .6);
    --mcb: rgba(139, 92, 246, .1);
}

.mode-card:nth-child(3) {
    --mc: rgba(245, 158, 11, .6);
    --mcb: rgba(245, 158, 11, .1);
}

.mode-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--mcb, rgba(59, 130, 246, .06));
    opacity: 0;
    transition: opacity .3s;
    border-radius: inherit;
}

.mode-card:hover {
    border-color: var(--mc, rgba(59, 130, 246, .6));
    box-shadow: 0 0 0 1px rgba(255, 255, 255, .08), 0 24px 60px rgba(0, 0, 0, .5), 0 0 50px var(--mc, rgba(59, 130, 246, .2));
    transform: translateY(-8px);
}

.mode-card:hover::after {
    opacity: 1;
}

.mode-badge {
    position: absolute;
    top: 16px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--txt2);
    text-transform: uppercase;
    opacity: .5;
}

.mode-card .icon {
    font-size: 36px;
    margin: 18px 0 12px;
    display: block;
    animation: floatY 3s ease-in-out infinite;
}

.mode-card:nth-child(2) .icon {
    animation-delay: .5s;
}

.mode-card:nth-child(3) .icon {
    animation-delay: 1s;
}

.mode-card h3 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -.2px;
}

.mode-card p {
    font-size: 13.5px;
    color: var(--txt2);
    line-height: 1.65;
    position: relative;
    z-index: 1;
}

/* ════════════════════════════════════════════════════════
   DOWNLOAD
══════════════════════════════════════════════════════════ */
.download {
    padding: 90px 0;
    text-align: center;
}

.download h2 {
    margin-bottom: 12px;
}

.download>.container>p {
    color: var(--txt2);
    margin-bottom: 40px;
    font-size: 15px;
}

.dl-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    max-width: 680px;
    margin: 0 auto;
}

.dl-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 22px;
    padding: 36px 32px;
    transition: all .35s;
    text-align: left;
}

.dl-card:hover {
    border-color: rgba(59, 130, 246, .4);
    transform: translateY(-6px);
    box-shadow: 0 20px 56px rgba(0, 0, 0, .5), 0 0 40px rgba(59, 130, 246, .15);
}

.dl-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
}

.dl-card p {
    font-size: 14px;
    color: var(--txt2);
    margin-bottom: 24px;
    line-height: 1.6;
}

/* ════════════════════════════════════════════════════════
   DONATION
══════════════════════════════════════════════════════════ */
.donation {
    padding: 90px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.donation::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 30% 50%, rgba(59, 130, 246, .06) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 50%, rgba(139, 92, 246, .06) 0%, transparent 60%);
    pointer-events: none;
}

.donation h2 {
    font-size: 30px;
    margin-bottom: 12px;
}

.donation>.container>p {
    color: var(--txt2);
    max-width: 520px;
    margin: 0 auto 40px;
    font-size: 15px;
    line-height: 1.7;
}

.donation-cards {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.donation-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 36px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 18px;
    font-weight: 700;
    font-size: 16px;
    color: var(--txt);
    text-decoration: none;
    transition: all .3s ease;
    min-width: 200px;
    text-align: left;
}

.donation-card:hover {
    transform: translateY(-5px);
    opacity: 1;
}

.donation-card.kofi {
    border-color: rgba(255, 94, 48, .35);
    animation: pulseBorder 3s ease infinite;
}

.donation-card.kofi:hover {
    border-color: rgba(255, 94, 48, .8);
    box-shadow: 0 12px 40px rgba(255, 94, 48, .25);
}

.donation-card.paypal {
    border-color: rgba(0, 114, 245, .35);
}

.donation-card.paypal:hover {
    border-color: rgba(0, 114, 245, .8);
    box-shadow: 0 12px 40px rgba(0, 114, 245, .25);
}

.donation-icon {
    font-size: 32px;
    line-height: 1;
}

/* ════════════════════════════════════════════════════════
   FOOTER
══════════════════════════════════════════════════════════ */
.footer {
    padding: 36px 0;
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 13px;
    color: var(--txt2);
}

.footer a {
    color: var(--accent);
}

/* ════════════════════════════════════════════════════════
   DOCS LAYOUT
══════════════════════════════════════════════════════════ */
.docs-layout {
    display: grid;
    grid-template-columns: 210px 1fr;
    gap: 48px;
    padding-top: 90px;
    padding-bottom: 60px;
    min-height: 100vh;
}

.sidebar {
    position: sticky;
    top: 80px;
    align-self: start;
    padding-right: 16px;
}

.sidebar a {
    display: block;
    padding: 7px 14px;
    color: var(--txt2);
    font-size: 13px;
    font-weight: 500;
    border-radius: 8px;
    margin-bottom: 2px;
    border-left: 2px solid transparent;
    transition: all .2s;
}

.sidebar a:hover {
    background: rgba(255, 255, 255, .04);
    color: var(--txt);
    opacity: 1;
}

.sidebar a.active {
    background: rgba(59, 130, 246, .08);
    color: var(--accent);
    border-left-color: var(--accent);
}

.docs-content {
    min-width: 0;
}

.docs-content h1 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: -.3px;
}

.docs-content h2 {
    font-size: 18px;
    font-weight: 600;
    margin: 36px 0 12px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
}

.docs-content h3 {
    font-size: 15px;
    font-weight: 600;
    margin: 24px 0 8px;
}

.docs-content p {
    margin-bottom: 12px;
    color: var(--txt2);
    line-height: 1.7;
}

.docs-content ul {
    margin: 8px 0 16px 20px;
    color: var(--txt2);
}

.docs-content li {
    margin-bottom: 5px;
    line-height: 1.6;
}

.docs-content code {
    background: rgba(59, 130, 246, .1);
    padding: 2px 7px;
    border-radius: 5px;
    font-size: 12.5px;
    color: #60a5fa;
    font-family: 'JetBrains Mono', monospace;
}

.docs-content pre {
    background: rgba(255, 255, 255, .04);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 18px;
    overflow-x: auto;
    margin: 12px 0 20px;
}

.docs-content pre code {
    background: none;
    padding: 0;
    color: var(--txt);
}

.docs-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
}

.docs-content th,
.docs-content td {
    padding: 10px 14px;
    border: 1px solid var(--border);
    text-align: left;
    font-size: 13px;
}

.docs-content th {
    background: rgba(255, 255, 255, .03);
    font-weight: 600;
    color: var(--txt);
}

.docs-content td {
    color: var(--txt2);
}

.docs-content tr:hover td {
    background: rgba(255, 255, 255, .02);
}

/* ════════════════════════════════════════════════════════
   SCROLL REVEAL (JS-applied)
══════════════════════════════════════════════════════════ */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .6s ease, transform .6s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* stagger delays */
.stagger-1 {
    transition-delay: .05s;
}

.stagger-2 {
    transition-delay: .12s;
}

.stagger-3 {
    transition-delay: .19s;
}

.stagger-4 {
    transition-delay: .26s;
}

.stagger-5 {
    transition-delay: .33s;
}

.stagger-6 {
    transition-delay: .40s;
}

/* ════════════════════════════════════════════════════════
   RESPONSIVE
══════════════════════════════════════════════════════════ */
/* Hẹp hơn 768px: menu dọc; 768–1100px: vẫn co cụm desktop có thể tràn — chuyển hamburger sớm hơn */
@media (max-width: 1100px) {
    .nav-links {
        display: none;
    }

    .nav-cta {
        display: none;
    }

    .nav-hamburger {
        display: flex;
    }

    .nav-toolbar {
        margin-left: auto;
    }
}

@media (max-width: 768px) {

    .hero {
        padding: 130px 0 70px;
    }

    .hero h1 {
        font-size: 34px;
        letter-spacing: -1px;
    }

    .docs-layout {
        grid-template-columns: 1fr;
        padding-top: 80px;
    }

    .sidebar {
        display: none;
    }

    .hero-stats {
        gap: 24px;
    }

    .dl-cards {
        grid-template-columns: 1fr;
        max-width: 100%;
    }

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

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

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

@media (max-width: 480px) {
    .hero h1 {
        font-size: 28px;
    }

    .btn {
        padding: 11px 20px;
        font-size: 13.5px;
    }

    .donation-cards {
        flex-direction: column;
        align-items: center;
    }

    .donation-card {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

/* ════════════════════════════════════════════════════════
   LIGHT THEME
══════════════════════════════════════════════════════════ */
[data-theme="light"] {
    --bg: #f8f8fc;
    --bg-mid: #f0f0f8;
    --bg-card: rgba(0, 0, 0, 0.05);
    --bg-card-h: rgba(0, 0, 0, 0.08);
    --txt: #1a1a28;
    --txt2: #666688;
    --border: rgba(0, 0, 0, 0.1);
    --border-h: rgba(0, 0, 0, 0.18);
    --shadow-glow: 0 0 50px rgba(59, 130, 246, 0.12);
}

[data-theme="light"] .nav {
    background: rgba(248, 248, 252, 0.88);
    border-bottom-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .nav.scrolled {
    background: rgba(248, 248, 252, 0.96);
    box-shadow: 0 4px 32px rgba(0, 0, 0, .12);
}

[data-theme="light"] .hero::before {
    background: radial-gradient(ellipse at 30% 40%, rgba(59, 130, 246, .1) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 60%, rgba(139, 92, 246, .08) 0%, transparent 60%);
}

[data-theme="light"] .feature-card {
    background: rgba(255, 255, 255, 0.8);
    border-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .mode-card {
    background: rgba(255, 255, 255, 0.85);
}

[data-theme="light"] .dl-card {
    background: rgba(255, 255, 255, 0.85);
    border-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .donation {
    background: #f5f5fa;
}

[data-theme="light"] .donation-card {
    background: rgba(255, 255, 255, 0.9);
    border-color: rgba(0, 0, 0, 0.12);
}

[data-theme="light"] .docs-content th {
    background: rgba(0, 0, 0, 0.04);
    color: var(--txt);
}

[data-theme="light"] .sidebar a {
    color: var(--txt2);
}

[data-theme="light"] .sidebar a.active {
    background: rgba(59, 130, 246, .1);
}

[data-theme="light"] .nav-mobile {
    background: rgba(245, 245, 250, .98);
}

[data-theme="light"] .lang-menu {
    background: rgba(245, 245, 250, .97);
}

[data-theme="light"] .hero::after {
    opacity: .5;
}

/* ════════════════════════════════════════════════════════
   LANGUAGE DROPDOWN  (replaces old .lang-toggle)
══════════════════════════════════════════════════════════ */
.lang-dropdown {
    position: relative;
    margin-left: 16px;
}

.lang-trigger {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: rgba(255, 255, 255, .06);
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--txt);
    cursor: pointer;
    transition: all .2s;
    white-space: nowrap;
    letter-spacing: .2px;
}

[data-theme="light"] .lang-trigger {
    background: rgba(0, 0, 0, .05);
    color: var(--txt);
}

.lang-trigger:hover {
    background: rgba(255, 255, 255, .10);
    border-color: var(--border-h);
}

[data-theme="light"] .lang-trigger:hover {
    background: rgba(0, 0, 0, .09);
}

.lang-trigger .chevron {
    font-size: 9px;
    opacity: .6;
    transition: transform .25s;
    margin-left: 2px;
}

.lang-dropdown.open .lang-trigger {
    border-color: rgba(59, 130, 246, .4);
}

.lang-dropdown.open .chevron {
    transform: rotate(180deg);
}

.lang-menu {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 150px;
    background: rgba(16, 16, 28, .95);
    border: 1px solid var(--border-h);
    border-radius: 14px;
    padding: 6px;
    box-shadow: 0 16px 40px rgba(0, 0, 0, .5), 0 0 0 1px rgba(255, 255, 255, .05);
    backdrop-filter: blur(20px);
    z-index: 200;
    animation: scaleIn .18s ease;
    transform-origin: top right;
}

.lang-dropdown.open .lang-menu {
    display: block;
}

.lang-option {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 12px;
    border-radius: 9px;
    font-size: 13px;
    font-weight: 500;
    color: var(--txt2);
    cursor: pointer;
    transition: all .18s;
    user-select: none;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.lang-option:hover {
    background: rgba(255, 255, 255, .07);
    color: var(--txt);
}

[data-theme="light"] .lang-option:hover {
    background: rgba(0, 0, 0, .06);
}

.lang-option.active {
    color: var(--txt);
    background: rgba(59, 130, 246, .12);
}

.lang-option .check {
    margin-left: auto;
    font-size: 12px;
    color: var(--accent);
}

/* ════════════════════════════════════════════════════════
   THEME TOGGLE BUTTON
══════════════════════════════════════════════════════════ */
.theme-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    margin-left: 8px;
    background: rgba(255, 255, 255, .06);
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 16px;
    cursor: pointer;
    transition: all .2s;
    line-height: 1;
    color: var(--txt);
}

[data-theme="light"] .theme-btn {
    background: rgba(0, 0, 0, .05);
}

.theme-btn:hover {
    background: rgba(255, 255, 255, .12);
    border-color: var(--border-h);
    transform: rotate(15deg) scale(1.05);
}

/* ════════════════════════════════════════════════════════
   ROTATING ORBIT BACKGROUND (hero)
══════════════════════════════════════════════════════════ */
@keyframes rotateOrbit {
    from {
        transform: translate(-50%, -50%) rotate(0deg);
    }

    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

@keyframes rotateOrbitReverse {
    from {
        transform: translate(-50%, -50%) rotate(0deg);
    }

    to {
        transform: translate(-50%, -50%) rotate(-360deg);
    }
}

.hero-orbit {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: min(700px, 95vw);
    height: min(700px, 95vw);
    pointer-events: none;
    z-index: 0;
    opacity: .045;
    animation: rotateOrbit 55s linear infinite;
}

.hero-orbit svg {
    width: 100%;
    height: 100%;
}

[data-theme="light"] .hero-orbit {
    opacity: .055;
}

/* Inner ring counter-rotates for depth */
.hero-orbit-inner {
    position: absolute;
    top: 50%;
    left: 50%;
    width: min(440px, 63vw);
    height: min(440px, 63vw);
    pointer-events: none;
    z-index: 0;
    opacity: .03;
    animation: rotateOrbitReverse 35s linear infinite;
}

.hero-orbit-inner svg {
    width: 100%;
    height: 100%;
}

/* ════════════════════════════════════════════════════════
   SUPPORTERS MARQUEE (unikorn-style)
══════════════════════════════════════════════════════════ */
.supporters {
    padding: 44px 0 40px;
    border-top: 1px solid var(--border);
}

.supporters-label {
    text-align: center;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1.8px;
    text-transform: uppercase;
    color: var(--txt2);
    margin-bottom: 20px;
    opacity: .55;
}

/* Unikorn-style: overflow hidden + mask-image for edge fade */
.marquee-wrap {
    overflow: hidden;
    max-width: 820px;
    margin: 0 auto;
    -webkit-mask-image: linear-gradient(to right, transparent 0%, black 14%, black 86%, transparent 100%);
    mask-image: linear-gradient(to right, transparent 0%, black 14%, black 86%, transparent 100%);
    display: flex;
    gap: 0;
}

@keyframes marqueeScroll {
    from {
        transform: translateX(0);
    }

    to {
        transform: translateX(-100%);
    }
}

/* Each .marquee-track is one set; both sets animate identically
   so they appear as one seamless stream */
.marquee-track {
    display: flex;
    flex-shrink: 0;
    gap: 0;
    animation: marqueeScroll 30s linear infinite;
    will-change: transform;
}

.marquee-wrap:hover .marquee-track {
    animation-play-state: paused;
}

.m-item {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 0 28px;
    font-size: 14px;
    font-weight: 600;
    color: var(--txt2);
    white-space: nowrap;
    transition: color .18s;
    cursor: default;
}

.m-item:hover {
    color: var(--txt);
}

.m-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
    border: 1px solid var(--border);
}

/* Emoji / chữ viết tắt thay ảnh PNG (tránh 404 khi chưa có assets/img) */
.m-avatar-text {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    line-height: 1;
    flex-shrink: 0;
    border: 1px solid var(--border);
    background: var(--bg-card);
}



/* ════════════════════════════════════════════════════════
   FIXES v3 — flags, nav alignment, marquee, footer, orbit
══════════════════════════════════════════════════════════ */

/* ── Flag image (flagcdn.com) ── */
.flag-img {
    width: 18px;
    height: 13px;
    border-radius: 2px;
    object-fit: cover;
    display: inline-block;
    vertical-align: middle;
    flex-shrink: 0;
}

.lang-trigger .flag-img {
    margin-right: 2px;
}

/* ── Nav alignment: all controls same height 34px ── */
.theme-btn,
.lang-trigger,
.nav-cta {
    height: 34px;
}

.lang-trigger {
    padding: 0 12px;
    gap: 7px;
}

.theme-btn {
    width: 34px;
    height: 34px;
    font-size: 15px;
}

/* ── Marquee: seamless, no gap ── */
.marquee-track {
    will-change: transform;
}

.marquee-item .sep {
    width: 1px;
    height: 16px;
    background: var(--border);
    margin: 0 8px;
}

/* ── Hero orbit: bigger, more opaque, better pattern ── */
.hero-orbit {
    width: min(820px, 115vw);
    height: min(820px, 115vw);
    opacity: .07;
    color: var(--accent);
}

.hero-orbit-inner {
    width: min(540px, 78vw);
    height: min(540px, 78vw);
    opacity: .055;
    color: var(--accent2);
}

[data-theme="light"] .hero-orbit {
    opacity: .09;
    color: #2563eb;
}

[data-theme="light"] .hero-orbit-inner {
    opacity: .065;
    color: #7c3aed;
}

/* ── Site footer (multi-column) ── */
.site-footer {
    background: var(--bg-mid);
    border-top: 1px solid var(--border);
    padding: 70px 0 32px;
    margin-top: 0;
}

.site-footer .footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.4fr;
    gap: 48px;
    margin-bottom: 56px;
}

.footer-brand h3 {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 20px;
    font-weight: 700;
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 12px;
}

.footer-brand p {
    font-size: 14px;
    color: var(--txt2);
    line-height: 1.65;
    max-width: 240px;
}

.footer-col h4 {
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 1.2px;
    text-transform: uppercase;
    color: var(--txt2);
    margin-bottom: 16px;
    opacity: .7;
}

.footer-col a {
    display: block;
    font-size: 14px;
    color: var(--txt2);
    margin-bottom: 10px;
    transition: color .2s;
}

.footer-col a:hover {
    color: var(--txt);
    opacity: 1;
}

.footer-donate a {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    color: var(--txt);
    border: 1px solid var(--border);
    margin-bottom: 10px;
    transition: all .2s;
    background: var(--bg-card);
}

.footer-donate a:hover {
    border-color: var(--border-h);
    transform: translateY(-2px);
}

.footer-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 28px;
    border-top: 1px solid var(--border);
    font-size: 13px;
    color: var(--txt2);
    flex-wrap: wrap;
    gap: 10px;
}

.footer-bar a {
    color: var(--accent);
    font-size: 13px;
}

/* ── Phosphor icons (inline SVG base style) ── */
.ph-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    vertical-align: middle;
    line-height: 1;
}

.feature-icon .ph-icon svg,
.feature-icon svg {
    width: 36px;
    height: 36px;
}

.mode-card .icon svg {
    width: 40px;
    height: 40px;
}

/* ── Docs nav — fixed layout: brand + links + controls all in one row ── */
.docs-nav .container {
    display: flex;
    align-items: center;
    gap: 0;
}

.docs-nav .nav-links {
    margin: 0 auto 0 24px;
}

.docs-nav .nav-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
}

/* ── Lang option flag ── */
.lang-option {
    gap: 8px;
}

/* Responsive footer */
@media (max-width: 768px) {
    .site-footer .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 36px;
    }
}

@media (max-width: 480px) {
    .site-footer .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-bar {
        flex-direction: column;
        text-align: center;
    }
}