:root {
    --bg: #eef3f8;
    --surface: #ffffff;
    --surface-2: #f7fafc;
    --surface-3: #f1f6fb;
    --line: #d8e2ec;
    --line-strong: #c4d3e2;

    --text: #102a43;
    --muted: #52667a;
    --muted-soft: #7b8ea4;

    --ac: #0b5fff;
    --ach: #2f80ff;
    --ac-g: rgba(11, 95, 255, 0.2);

    --ok: #1f9d68;

    --radius-lg: 18px;
    --radius-md: 14px;
    --radius-sm: 10px;
    --radius-pill: 999px;

    --f-title: "Nunito Sans", "Public Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --f-body: "Public Sans", "Manrope", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --f-mono: "IBM Plex Mono", "SF Mono", Menlo, Monaco, Consolas, monospace;

    --container-w: 1120px;
    --shadow-soft: 0 10px 24px rgba(12, 27, 61, 0.08);
    --shadow-strong: 0 14px 32px rgba(12, 27, 61, 0.12);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 102px;
}

body {
    font-family: var(--f-body);
    color: var(--text);
    line-height: 1.66;
    min-height: 100vh;
    overflow-x: hidden;
    background:
        radial-gradient(circle at 92% 6%, rgba(11, 95, 255, 0.12) 0%, transparent 32%),
        linear-gradient(180deg, #f8fbff 0%, var(--bg) 35%, var(--bg) 100%);
    -webkit-font-smoothing: antialiased;
}

::selection {
    background: rgba(11, 95, 255, 0.18);
    color: #081528;
}

.bg-depth {
    position: fixed;
    width: 300px;
    height: 300px;
    border-radius: 999px;
    right: -120px;
    top: -120px;
    filter: blur(72px);
    pointer-events: none;
    z-index: -1;
    background: rgba(11, 95, 255, 0.38);
    opacity: 0.32;
}

h1,
h2,
h3,
h4 {
    font-family: var(--f-title);
    letter-spacing: -0.02em;
    line-height: 1.16;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
}

/* Header */
.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 40;
    padding: 0.85rem 1rem;
    display: flex;
    justify-content: center;
}

.nav-container {
    width: min(100%, var(--container-w));
    border-radius: var(--radius-pill);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    padding: 0.58rem 0.95rem 0.58rem 1.08rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    box-shadow: var(--shadow-soft);
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.56rem;
    font-weight: 800;
    font-size: 0.95rem;
    color: #0f2e4e;
}

.logo img {
    width: 24px;
    height: 24px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    color: var(--muted);
    font-size: 0.9rem;
}

.nav-links a:hover {
    color: var(--text);
}

.nav-divider {
    width: 1px;
    height: 16px;
    background: #d6e2ee;
}

.lang-btn,
.nav-btn-github {
    height: 34px;
    border-radius: var(--radius-pill);
    border: 1px solid #c8d6e7;
    background: #ffffff;
    color: var(--text);
    padding: 0 0.85rem;
    font-size: 0.83rem;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    cursor: pointer;
    transition: 160ms ease;
}

.lang-btn {
    font-family: var(--f-body);
}

.lang-btn:hover,
.nav-btn-github:hover {
    border-color: #9cb6d5;
    transform: translateY(-1px);
}

/* Sections */
main {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
}

.section,
.hero {
    width: min(100%, var(--container-w));
    padding-left: 1.2rem;
    padding-right: 1.2rem;
}

.hero {
    padding-top: 7.1rem;
    padding-bottom: 4.7rem;
    text-align: center;
}

.hero .badge,
.section-badge {
    display: inline-flex;
    align-items: center;
    border-radius: var(--radius-pill);
    border: 1px solid #c8d6e7;
    background: #f4f8fd;
    color: #3c5471;
    padding: 0.26rem 0.72rem;
    text-transform: uppercase;
    font-family: var(--f-mono);
    font-size: 0.68rem;
    letter-spacing: 0.07em;
}

.hero .badge {
    margin-bottom: 1rem;
}

.hero-title {
    font-size: clamp(2.2rem, 5.5vw, 4.2rem);
    margin-bottom: 0.9rem;
    color: #0d2c4c;
}

.hero-desc {
    max-width: 68ch;
    margin: 0 auto;
    color: var(--muted);
    font-size: 1.02rem;
}

.cta-group {
    margin-top: 1.5rem;
    margin-bottom: 1.8rem;
    display: flex;
    justify-content: center;
    gap: 0.72rem;
    flex-wrap: wrap;
}

.btn {
    height: 44px;
    border-radius: var(--radius-pill);
    padding: 0 1.15rem;
    border: 1px solid transparent;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.88rem;
    font-weight: 700;
    transition: 160ms ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    color: #ffffff;
    background: linear-gradient(120deg, var(--ac), var(--ach));
    box-shadow: 0 10px 20px rgba(11, 95, 255, 0.22);
}

.btn-secondary {
    color: #244666;
    border-color: #c8d8ea;
    background: #ffffff;
}

.btn-secondary:hover {
    border-color: #a8c0db;
}

.hero-abstract {
    width: min(100%, 760px);
    margin: 0 auto;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
    padding: 1rem;
    text-align: left;
}

.abstract-line {
    display: grid;
    grid-template-columns: 10px 1fr auto;
    align-items: center;
    gap: 0.62rem;
    padding: 0.45rem 0;
    border-bottom: 1px dashed #dfebf6;
}

.abstract-line:last-of-type {
    border-bottom: none;
}

.ab-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--ac);
}

.ab-text {
    color: #224567;
    font-size: 0.84rem;
}

.ab-code {
    font-family: var(--f-mono);
    color: #56728f;
    font-size: 0.74rem;
    background: #f4f8fd;
    border: 1px solid #d8e5f2;
    border-radius: 6px;
    padding: 0.2rem 0.45rem;
}

.abstract-arrow {
    text-align: center;
    color: #6f86a0;
    margin: 0.7rem 0;
}

.abstract-output {
    border: 1px solid #d7e4f0;
    border-radius: 10px;
    overflow: hidden;
    background: #fcfdff;
}

.out-header {
    padding: 0.55rem 0.72rem;
    background: #f3f8fe;
    color: #31516f;
    font-size: 0.77rem;
    font-weight: 700;
}

.out-body {
    padding: 0.72rem;
    display: grid;
    gap: 0.45rem;
}

.out-block {
    height: 8px;
    border-radius: 999px;
    background: #d9e6f4;
}

.out-block.w-full {
    width: 100%;
}

.out-block.w-3\/4 {
    width: 75%;
}

.out-block.w-1\/2 {
    width: 50%;
}

.out-image {
    height: 110px;
    border-radius: 8px;
    border: 1px solid #d9e6f4;
    background: linear-gradient(140deg, #e8f1fb, #f7fbff);
}

/* Content sections */
.section {
    padding-top: 4.3rem;
    padding-bottom: 4.3rem;
    text-align: center;
}

.section-badge {
    margin-bottom: 0.9rem;
}

.section-title {
    font-size: clamp(1.7rem, 4vw, 2.7rem);
    color: #133352;
    margin-bottom: 0.7rem;
}

.section-desc {
    max-width: 62ch;
    margin: 0 auto 2.4rem;
    color: var(--muted);
}

.bento-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.95rem;
}

.bento-card {
    text-align: left;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
    padding: 1.05rem;
    transition: 180ms ease;
}

.bento-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-strong);
}

.col-span-2 {
    grid-column: span 2;
}

.card-icon {
    width: 30px;
    height: 30px;
    border-radius: 8px;
    border: 1px solid #d6e4f2;
    background: #f3f8fe;
    color: #2d5174;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.62rem;
}

.card-icon svg {
    width: 16px;
    height: 16px;
}

.bento-card h3 {
    font-size: 1.03rem;
    color: #173859;
    margin-bottom: 0.36rem;
}

.bento-card p {
    color: var(--muted);
    font-size: 0.9rem;
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.95rem;
}

.uc-card {
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
    padding: 1.05rem;
    text-align: left;
    display: flex;
    gap: 0.78rem;
    transition: 180ms ease;
}

.uc-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-strong);
}

.uc-num {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-pill);
    background: linear-gradient(120deg, var(--ac), var(--ach));
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.uc-content h4 {
    margin-bottom: 0.28rem;
    color: #163756;
    font-size: 1rem;
}

.uc-content p {
    font-size: 0.89rem;
    color: var(--muted);
}

.steps-container {
    width: min(100%, 820px);
    display: grid;
    gap: 0.72rem;
}

.step {
    display: grid;
    grid-template-columns: 36px 1fr;
    align-items: start;
    gap: 0.72rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
    padding: 0.95rem;
    text-align: left;
}

.step-num-large {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-pill);
    background: linear-gradient(120deg, var(--ac), var(--ach));
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.77rem;
    font-weight: 700;
}

.step-line {
    display: none;
}

.step-info h3 {
    color: #173859;
    font-size: 1rem;
    margin-bottom: 0.2rem;
}

.step-info p {
    color: var(--muted);
    font-size: 0.9rem;
}

/* Footer */
footer {
    width: min(100%, var(--container-w));
    padding: 1.3rem 1.2rem 2.3rem;
    margin: 0 auto;
}

.footer-content {
    max-width: 760px;
    margin: 0 auto;
    padding: 0.15rem 0 0;
    text-align: center;
}

.f-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 800;
    color: #123353;
    margin-bottom: 0.42rem;
}

.f-brand img {
    width: 22px;
    height: 22px;
    filter: none !important;
}

.f-desc {
    color: var(--muted);
    font-size: 0.88rem;
    margin-bottom: 0.85rem;
}

.f-links {
    display: inline-flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.72rem;
    margin-bottom: 0.45rem;
}

.f-links a {
    color: #2a4f74;
    font-size: 0.84rem;
}

.f-links a:hover {
    color: var(--ac);
}

.copyright {
    color: #6d8399;
    font-size: 0.78rem;
}

/* Animations */
.fade-in {
    animation: fadeIn 0.5s ease-out;
}

.slide-up {
    animation: slideUp 0.62s ease-out;
}

.fade-in-delay {
    animation: fadeIn 0.7s ease-out 0.18s both;
}

.slide-up-reveal {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.45s ease, transform 0.45s ease;
}

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

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }

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

/* Responsive */
@media (max-width: 920px) {
    .nav-container {
        padding: 0.55rem 0.7rem 0.55rem 0.86rem;
    }

    .nav-links {
        gap: 0.65rem;
        font-size: 0.82rem;
    }

    .bento-grid,
    .use-cases-grid {
        grid-template-columns: 1fr;
    }

    .col-span-2 {
        grid-column: span 1;
    }
}

@media (max-width: 680px) {
    .nav-header {
        padding: 0.6rem;
    }

    .nav-links a,
    .nav-divider {
        display: none;
    }

    .hero {
        padding-top: 6.3rem;
        padding-bottom: 3.8rem;
    }

    .hero-desc {
        font-size: 0.95rem;
    }

    .cta-group {
        gap: 0.56rem;
    }

    .btn {
        width: 100%;
    }

    .abstract-line {
        grid-template-columns: 10px 1fr;
    }

    .ab-code {
        grid-column: 2;
        width: fit-content;
    }

    .section {
        padding-top: 3.4rem;
        padding-bottom: 3.4rem;
    }
}

.demo-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.95rem;
}

.demo-card {
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-soft);
    overflow: hidden;
    text-align: left;
    transition: 180ms ease;
}

.demo-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-strong);
}

.demo-media {
    width: 100%;
    display: block;
    border-bottom: 1px solid #d9e6f4;
    background: #eef4ff;
}

.demo-copy {
    padding: 0.95rem 1rem;
}

.demo-copy h3 {
    font-size: 1.02rem;
    color: #173859;
    margin-bottom: 0.24rem;
}

.demo-copy p {
    font-size: 0.9rem;
    color: var(--muted);
}