/*
 * Design Philosophy: Neo-Editorial Streamscape.
 * The interface blends cinematic glassmorphism, editorial spacing,
 * cool midnight tones, and responsive content grids for a premium video portal.
 */

:root {
    --bg: #07111c;
    --bg-soft: #0c1624;
    --panel: rgba(13, 22, 36, 0.72);
    --panel-strong: rgba(17, 28, 44, 0.92);
    --line: rgba(160, 197, 255, 0.14);
    --line-strong: rgba(131, 183, 255, 0.24);
    --text: #f2f7ff;
    --text-soft: #adc1dd;
    --text-muted: #7d93ae;
    --accent: #7ee0ff;
    --accent-strong: #5aa8ff;
    --accent-warm: #ffc98c;
    --shadow: 0 28px 70px rgba(0, 0, 0, 0.32);
    --radius-xl: 32px;
    --radius-lg: 24px;
    --radius-md: 18px;
    --radius-sm: 12px;
    --container: min(1280px, calc(100vw - 32px));
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background:
        radial-gradient(circle at top left, rgba(59, 118, 255, 0.24), transparent 28%),
        radial-gradient(circle at 85% 8%, rgba(31, 200, 255, 0.18), transparent 24%),
        linear-gradient(180deg, #07111c 0%, #091320 52%, #060d17 100%);
    line-height: 1.7;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 120px 120px;
    opacity: 0.3;
    mix-blend-mode: soft-light;
}

img {
    display: block;
    width: 100%;
    height: auto;
}

a,
button,
input,
textarea,
select,
img {
    transition: all 0.28s ease;
}

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

button,
input,
textarea,
select {
    font: inherit;
}

.site-shell {
    position: relative;
    z-index: 1;
    width: var(--container);
    margin: 0 auto;
    padding: 24px 0 48px;
}

.glass-panel {
    background: linear-gradient(180deg, rgba(18, 29, 45, 0.88), rgba(9, 17, 28, 0.75));
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    backdrop-filter: blur(22px);
    -webkit-backdrop-filter: blur(22px);
}

.topbar {
    position: sticky;
    top: 18px;
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 28px;
    align-items: center;
    padding: 18px 22px;
    border-radius: 999px;
    margin-bottom: 28px;
    z-index: 40;
}

.brand-mark {
    display: inline-flex;
    align-items: center;
    gap: 14px;
    min-width: 0;
}

.brand-mark__icon {
    display: grid;
    place-items: center;
    width: 54px;
    height: 54px;
    border-radius: 18px;
    font-weight: 800;
    letter-spacing: 0.08em;
    color: #03111f;
    background: linear-gradient(135deg, var(--accent), #f2fbff);
    box-shadow: 0 12px 36px rgba(88, 173, 255, 0.34);
}

.brand-mark__text {
    display: grid;
    gap: 4px;
}

.brand-mark__text strong {
    font-size: 1rem;
    letter-spacing: 0.04em;
}

.brand-mark__text small {
    color: var(--text-soft);
    font-size: 0.72rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.topbar__nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.topbar__link {
    padding: 10px 14px;
    border-radius: 999px;
    color: var(--text-soft);
    font-size: 0.94rem;
}

.topbar__link:hover,
.topbar__link:focus-visible {
    color: var(--text);
    background: rgba(255, 255, 255, 0.06);
}

.topbar__actions {
    display: inline-flex;
    align-items: center;
    gap: 12px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    border: 1px solid transparent;
    border-radius: 999px;
    padding: 12px 20px;
    font-weight: 700;
    cursor: pointer;
}

.button--primary {
    color: #03101e;
    background: linear-gradient(135deg, #7ee0ff, #7fa7ff);
    box-shadow: 0 14px 34px rgba(85, 154, 255, 0.24);
}

.button--primary:hover,
.button--primary:focus-visible {
    transform: translateY(-1px);
    box-shadow: 0 18px 42px rgba(85, 154, 255, 0.32);
}

.button--ghost {
    color: var(--text);
    background: rgba(255, 255, 255, 0.04);
    border-color: var(--line);
}

.button--ghost:hover,
.button--ghost:focus-visible {
    border-color: var(--line-strong);
    background: rgba(255, 255, 255, 0.08);
}

.hero {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 22px;
    margin-bottom: 28px;
}

.hero__copy,
.hero__visual,
.page-hero,
.detail-hero,
.section__column,
.section-card,
.site-footer,
.prose-block {
    border-radius: var(--radius-xl);
}

.hero__copy,
.hero__visual {
    padding: 34px;
}

.hero__copy h1,
.page-hero h1,
.detail-hero h1 {
    margin: 0 0 18px;
    font-size: clamp(2rem, 4vw, 4.3rem);
    line-height: 1.06;
    letter-spacing: -0.03em;
}

.hero__copy p,
.page-hero p,
.detail-hero p,
.prose-block p {
    margin: 0;
    color: var(--text-soft);
}

.eyebrow {
    margin-bottom: 12px;
    color: var(--accent);
    font-size: 0.8rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 26px;
}

.hero__stats,
.metrics-grid,
.two-up-grid,
.video-grid,
.featured-grid,
.topic-grid,
.detail-panels,
.section--split {
    display: grid;
    gap: 18px;
}

.hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    margin-top: 32px;
}

.stat-card,
.metric-card {
    padding: 18px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.stat-card strong,
.metric-card strong {
    display: block;
    font-size: 1.75rem;
    line-height: 1;
    margin-bottom: 6px;
}

.stat-card span,
.metric-card span,
.video-card__meta,
.submission-card__meta,
.topic-card__kicker,
.page-hero__meta,
.detail-meta,
.site-footer p,
.empty-state {
    color: var(--text-muted);
}

.hero__visual {
    position: relative;
    min-height: 530px;
    overflow: hidden;
}

.hero__visual img,
.detail-hero__media img,
.video-card__media img {
    height: 100%;
    object-fit: cover;
    border-radius: inherit;
}

.hero__floating {
    position: absolute;
    left: 24px;
    right: 24px;
    bottom: 24px;
    padding: 18px;
    border-radius: var(--radius-lg);
    background: rgba(8, 14, 24, 0.72);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.keyword-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 14px;
}

.keyword-cloud--dense {
    margin-top: 0;
}

.keyword-link,
.chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    border-radius: 999px;
    padding: 8px 12px;
    font-size: 0.82rem;
    line-height: 1;
}

.keyword-link {
    color: var(--text);
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.keyword-link:hover,
.keyword-link:focus-visible {
    transform: translateY(-2px);
    border-color: rgba(126, 224, 255, 0.36);
    background: rgba(126, 224, 255, 0.14);
}

.chip {
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.chip--primary {
    color: #041220;
    background: linear-gradient(135deg, #7ee0ff, #a9c7ff);
}

.chip--quiet {
    color: var(--text-soft);
    background: rgba(255, 255, 255, 0.04);
}

.section {
    margin-top: 26px;
}

.section__head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 18px;
}

.section__head h2,
.prose-block h2,
.prose-block h3,
.section-card h2 {
    margin: 0;
    font-size: clamp(1.4rem, 2vw, 2rem);
}

.section__head--compact {
    margin-bottom: 16px;
}

.text-link {
    color: var(--accent);
    font-weight: 700;
}

.text-link:hover,
.text-link:focus-visible {
    color: #d7f7ff;
}

.text-link--muted {
    color: var(--text-muted);
}

.featured-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.video-grid,
.video-grid--compact {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.video-card,
.topic-card,
.submission-card {
    display: flex;
    flex-direction: column;
    min-width: 0;
    border-radius: var(--radius-lg);
    background: rgba(9, 16, 28, 0.78);
    border: 1px solid rgba(255, 255, 255, 0.08);
    overflow: hidden;
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.22);
}

.video-card:hover,
.topic-card:hover,
.submission-card:hover {
    transform: translateY(-4px);
    border-color: rgba(126, 224, 255, 0.24);
}

.video-card__media {
    display: block;
    aspect-ratio: 16 / 10;
    overflow: hidden;
}

.video-card__media img {
    transform: scale(1.01);
}

.video-card:hover .video-card__media img {
    transform: scale(1.05);
}

.video-card__body,
.topic-card,
.submission-card {
    padding: 18px;
}

.video-card__meta-row,
.video-card__footer,
.topic-card__footer,
.submission-card__footer,
.submission-card__meta,
.page-hero,
.page-hero__meta,
.detail-meta,
.search-layer__head,
.breadcrumb-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
}

.video-card__title,
.topic-card__title,
.submission-card__title {
    margin: 14px 0 12px;
    font-size: 1.22rem;
    line-height: 1.3;
}

.video-card__title--lg {
    font-size: 1.38rem;
}

.video-card__summary,
.topic-card__summary,
.submission-card__summary,
.stack-item p {
    margin: 0;
    color: var(--text-soft);
    font-size: 0.96rem;
}

.video-card__tags,
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 16px;
}

.video-card__footer,
.topic-card__footer,
.submission-card__footer {
    margin-top: auto;
    padding-top: 18px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.topic-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.topic-card__kicker {
    font-size: 0.75rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.section--split,
.two-up-grid,
.detail-panels {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.section__column,
.section-card,
.prose-block,
.page-hero,
.detail-hero {
    padding: 26px;
}

.stack-list {
    display: grid;
    gap: 14px;
}

.stack-item {
    padding-bottom: 14px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.stack-item:last-child {
    padding-bottom: 0;
    border-bottom: none;
}

.stack-item h3 {
    margin: 0 0 8px;
    font-size: 1.08rem;
}

.page-hero {
    margin-top: 8px;
}

.pagination {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 24px;
}

.pagination__link {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: 16px;
    color: var(--text-soft);
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.pagination__link--active,
.pagination__link:hover,
.pagination__link:focus-visible {
    color: #041220;
    background: linear-gradient(135deg, #7ee0ff, #a9c7ff);
}

.detail-layout {
    margin-top: 8px;
}

.detail-hero {
    display: grid;
    grid-template-columns: 0.92fr 1.08fr;
    gap: 24px;
}

.detail-hero__media {
    border-radius: var(--radius-lg);
    overflow: hidden;
    min-height: 460px;
}

.breadcrumb-row {
    color: var(--text-muted);
    font-size: 0.92rem;
    margin-bottom: 16px;
}

.detail-meta {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.tag-list {
    list-style: none;
    padding: 0;
    margin: 16px 0 0;
}

.tag-list li {
    padding: 10px 14px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.notice {
    margin-bottom: 16px;
    padding: 14px 16px;
    border-radius: var(--radius-md);
    font-size: 0.94rem;
}

.notice--success {
    color: #d4fff0;
    background: rgba(31, 139, 96, 0.18);
    border: 1px solid rgba(86, 231, 174, 0.25);
}

.notice--error {
    color: #ffe2e2;
    background: rgba(168, 45, 45, 0.18);
    border: 1px solid rgba(255, 130, 130, 0.28);
}

.submit-form {
    display: grid;
    gap: 14px;
}

.submit-form label {
    display: grid;
    gap: 8px;
}

.submit-form span {
    color: var(--text-soft);
    font-weight: 600;
}

.submit-form input,
.submit-form textarea,
.submit-form select,
.search-form input {
    width: 100%;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 14px 16px;
    color: var(--text);
    background: rgba(255, 255, 255, 0.04);
    outline: none;
}

.submit-form input:focus,
.submit-form textarea:focus,
.submit-form select:focus,
.search-form input:focus {
    border-color: rgba(126, 224, 255, 0.45);
    box-shadow: 0 0 0 4px rgba(126, 224, 255, 0.08);
}

.hidden-field {
    position: absolute;
    left: -9999px;
    opacity: 0;
}

.site-footer {
    display: grid;
    grid-template-columns: 1.3fr 0.7fr;
    gap: 24px;
    margin-top: 26px;
    padding: 28px;
}

.site-footer h2 {
    margin: 0 0 10px;
}

.site-footer__links {
    display: grid;
    gap: 10px;
    justify-items: start;
}

.site-footer__links a {
    color: var(--text-soft);
}

.site-footer__links a:hover,
.site-footer__links a:focus-visible {
    color: var(--accent);
}

.search-layer {
    position: fixed;
    inset: 0;
    z-index: 120;
}

.search-layer__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(4, 8, 14, 0.74);
}

.search-layer__panel {
    position: relative;
    width: min(760px, calc(100vw - 24px));
    margin: 10vh auto 0;
    padding: 26px;
    border-radius: 28px;
}

.search-form {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 12px;
    margin-top: 16px;
}

.search-suggestions {
    margin-top: 18px;
}

.empty-state {
    margin: 0;
}

@media (max-width: 1100px) {
    .topbar {
        grid-template-columns: 1fr;
        justify-items: start;
        border-radius: 28px;
    }

    .topbar__nav,
    .topbar__actions {
        justify-content: flex-start;
    }

    .hero,
    .detail-hero,
    .section--split,
    .two-up-grid,
    .detail-panels,
    .site-footer {
        grid-template-columns: 1fr;
    }

    .hero__stats,
    .video-grid,
    .topic-grid,
    .featured-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 760px) {
    .site-shell {
        width: min(100vw - 20px, 100%);
        padding-top: 14px;
    }

    .topbar,
    .hero__copy,
    .hero__visual,
    .page-hero,
    .detail-hero,
    .section__column,
    .section-card,
    .prose-block,
    .site-footer,
    .search-layer__panel {
        padding: 20px;
    }

    .hero__stats,
    .metrics-grid,
    .video-grid,
    .topic-grid,
    .featured-grid,
    .video-grid--compact {
        grid-template-columns: 1fr;
    }

    .brand-mark {
        align-items: flex-start;
    }

    .brand-mark__text small {
        max-width: 28ch;
    }

    .hero__visual {
        min-height: 360px;
    }

    .detail-hero__media {
        min-height: 280px;
    }

    .search-form {
        grid-template-columns: 1fr;
    }
}