:root {
    --bg: #fff1de;
    --bg-cool: #ddfff8;
    --surface: #ffffff;
    --surface-soft: #edf7ff;
    --surface-warm: #fff4c7;
    --ink: #13243d;
    --ink-soft: #3d5876;
    --brand: #ff3d00;
    --brand-strong: #bf2900;
    --brand-cool: #00cdb6;
    --brand-cool-strong: #008d7f;
    --accent: #ffd400;
    --accent-soft: #ffed7a;
    --border: #b8d8f2;
    --shadow-lg: 0 20px 46px rgba(16, 32, 56, 0.2);
    --shadow-md: 0 12px 32px rgba(16, 32, 56, 0.13);
    --radius-lg: 22px;
    --radius-md: 14px;
    --radius-sm: 10px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: 'Manrope', sans-serif;
    color: var(--ink);
    background:
        radial-gradient(circle at 6% 8%, rgba(255, 61, 0, 0.36), transparent 36%),
        radial-gradient(circle at 95% 0%, rgba(0, 205, 182, 0.34), transparent 34%),
        radial-gradient(circle at 50% 110%, rgba(255, 212, 0, 0.26), transparent 48%),
        linear-gradient(160deg, var(--bg) 0%, var(--bg-cool) 100%);
    line-height: 1.65;
}

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

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

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    background: var(--brand-strong);
    color: #ffffff;
    padding: 0.6rem 0.9rem;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    z-index: 120;
    font-weight: 700;
}

.skip-link:focus {
    left: 0.75rem;
}

.container {
    width: min(1120px, calc(100% - 2rem));
    margin: 0 auto;
}

.topbar {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(12px);
    background: rgba(255, 255, 255, 0.9);
    border-bottom: 1px solid rgba(184, 216, 242, 0.95);
}

.nav-wrap {
    padding: 0.95rem 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.brand {
    font-family: 'Fraunces', serif;
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: 0.01em;
    color: var(--brand-strong);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    flex-wrap: wrap;
}

.nav-links a {
    padding: 0.45rem 0.88rem;
    border-radius: 999px;
    font-weight: 700;
    color: var(--ink-soft);
    border: 1px solid transparent;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
    border-color: rgba(0, 169, 157, 0.34);
    background-color: rgba(0, 169, 157, 0.1);
    color: var(--ink);
}

.nav-links a.active {
    border-color: transparent;
    background: linear-gradient(120deg, var(--brand), var(--brand-cool));
    color: #ffffff;
}

main {
    padding-bottom: 3.5rem;
}

.hero {
    padding: 4.8rem 0 2.5rem;
}

.hero-grid {
    display: grid;
    gap: 1.7rem;
    grid-template-columns: 1.15fr 0.85fr;
    align-items: end;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-weight: 800;
    font-size: 0.72rem;
    color: var(--brand-cool-strong);
    padding: 0.35rem 0.7rem;
    border-radius: 999px;
    border: 1px solid rgba(0, 169, 157, 0.35);
    background: rgba(0, 169, 157, 0.1);
}

h1,
h2,
h3 {
    margin: 0;
    font-family: 'Fraunces', serif;
    letter-spacing: -0.01em;
}

.hero h1 {
    margin-top: 1rem;
    font-size: clamp(2rem, 5vw, 3.75rem);
    line-height: 1.08;
}

.hero p {
    margin: 1.1rem 0 0;
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--ink-soft);
    max-width: 60ch;
}

.hero-meta {
    background: linear-gradient(145deg, #ffffff 0%, #f0fffb 42%, #fff9dc 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 1.4rem;
}

.hero-meta h3 {
    font-size: 1.2rem;
}

.meta-list {
    margin: 1rem 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.75rem;
}

.meta-list li {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.65rem;
    align-items: start;
    color: var(--ink-soft);
    font-weight: 600;
}

.meta-dot {
    width: 0.62rem;
    height: 0.62rem;
    border-radius: 50%;
    margin-top: 0.45rem;
    background: linear-gradient(140deg, var(--brand), var(--accent));
}

.section-head {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 1rem;
    margin: 1.8rem 0 1.2rem;
}

.section-head h2 {
    font-size: clamp(1.45rem, 3vw, 2.1rem);
}

.section-head p {
    margin: 0;
    color: var(--ink-soft);
    font-weight: 600;
}

.post-grid {
    display: grid;
    gap: 1.2rem;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.post-card {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1.2rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    background: linear-gradient(150deg, #ffffff 0%, #ecf7ff 48%, #fff7d6 100%);
    box-shadow: var(--shadow-md);
    transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(255, 90, 47, 0.38);
}

.post-tag {
    display: inline-flex;
    padding: 0.26rem 0.65rem;
    border-radius: 999px;
    background: rgba(255, 202, 58, 0.28);
    color: #6d4c0a;
    font-size: 0.73rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    width: fit-content;
}

.post-card h3 {
    font-size: 1.35rem;
}

.post-card p {
    margin: 0;
    color: var(--ink-soft);
}

.post-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-weight: 800;
    color: var(--brand-strong);
}

.post-link::after {
    content: '->';
    transition: transform 0.2s ease;
}

.post-card:hover .post-link::after {
    transform: translateX(4px);
}

.topic-band {
    margin-top: 2.4rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.2rem;
    background: linear-gradient(130deg, rgba(0, 205, 182, 0.24), rgba(255, 212, 0, 0.28), rgba(255, 61, 0, 0.14));
}

.topic-list {
    margin: 0.75rem 0 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.55rem;
}

.topic-list li {
    padding: 0.38rem 0.7rem;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.86);
    border: 1px solid rgba(19, 36, 61, 0.14);
    font-weight: 700;
    font-size: 0.88rem;
}

.newsletter {
    margin-top: 2rem;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 1rem;
    align-items: center;
    background: linear-gradient(120deg, #ff3d00 0%, #ff7a00 34%, #ffd400 63%, #00cdb6 100%);
    color: #ffffff;
    border-radius: var(--radius-lg);
    padding: 1.6rem;
    box-shadow: var(--shadow-lg);
}

.newsletter p {
    margin: 0.6rem 0 0;
    color: rgba(255, 255, 255, 0.9);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 0;
    border-radius: 999px;
    padding: 0.62rem 1.1rem;
    font-weight: 700;
    transition: transform 0.2s ease, opacity 0.2s ease;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
    opacity: 0.95;
}

.btn-accent {
    background: #ffffff;
    color: var(--brand-strong);
    border: 1px solid rgba(255, 255, 255, 0.7);
}

.btn-primary {
    background: linear-gradient(120deg, var(--brand), var(--brand-cool));
    color: #ffffff;
}

.site-footer {
    border-top: 1px solid rgba(204, 222, 238, 0.95);
    padding: 1.5rem 0 2.2rem;
    color: var(--ink-soft);
    font-weight: 700;
}

.site-footer p {
    margin: 0;
}

.article-hero {
    padding: 3.9rem 0 2rem;
}

.article-hero h1 {
    margin-top: 0.7rem;
    font-size: clamp(1.95rem, 4vw, 3.2rem);
    line-height: 1.12;
    max-width: 22ch;
}

.article-hero p {
    margin: 1rem 0 0;
    color: var(--ink-soft);
    max-width: 65ch;
}

.article-meta {
    margin-top: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.9rem;
    color: var(--ink-soft);
    font-weight: 700;
    font-size: 0.95rem;
}

.status-note {
    margin-top: 1rem;
    width: fit-content;
    padding: 0.5rem 0.82rem;
    border-radius: 999px;
    border: 1px solid rgba(191, 41, 0, 0.3);
    background: rgba(255, 212, 0, 0.3);
    color: #6b2a00;
    font-weight: 800;
    font-size: 0.86rem;
}

.article-layout {
    display: grid;
    gap: 1.4rem;
    grid-template-columns: minmax(0, 1fr) 280px;
    align-items: start;
}

.article-content {
    background: linear-gradient(150deg, #ffffff 0%, #f1f8ff 53%, #fff8e1 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
}

.article-content > * + * {
    margin-top: 1rem;
}

.article-content h2 {
    margin-top: 1.6rem;
    font-size: clamp(1.3rem, 2.4vw, 1.8rem);
}

.article-content h3 {
    margin-top: 1.1rem;
    font-size: 1.2rem;
}

.article-content p,
.article-content li {
    color: var(--ink-soft);
}

.article-content pre {
    margin: 1rem 0;
    padding: 0.95rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(19, 36, 61, 0.15);
    background: #0f223b;
    overflow-x: auto;
}

.article-content code {
    font-family: 'IBM Plex Mono', 'Cascadia Code', Consolas, monospace;
    font-size: 0.88rem;
    color: #1f3d5d;
    background: rgba(31, 61, 93, 0.1);
    padding: 0.08rem 0.28rem;
    border-radius: 5px;
}

.article-content pre code {
    color: #ecf5ff;
    background: transparent;
    padding: 0;
}

.article-content ul,
.article-content ol {
    padding-left: 1.2rem;
    margin: 0;
}

.article-content blockquote {
    margin: 1rem 0;
    padding: 0.95rem 1rem;
    border-left: 4px solid var(--brand-cool);
    border-radius: var(--radius-sm);
    background: rgba(0, 169, 157, 0.12);
    color: #1b5f6a;
    font-weight: 700;
}

.article-callout {
    margin: 1.2rem 0;
    padding: 1rem;
    border-left: 4px solid var(--brand);
    border-radius: var(--radius-sm);
    background: var(--surface-warm);
}

.article-aside {
    position: sticky;
    top: 5.5rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: linear-gradient(150deg, rgba(255, 255, 255, 0.97), rgba(221, 255, 248, 0.95), rgba(255, 246, 221, 0.95));
    padding: 1rem;
}

.article-aside h3 {
    font-size: 1rem;
    margin-bottom: 0.55rem;
}

.article-aside ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.65rem;
}

.article-aside li {
    font-size: 0.9rem;
    color: var(--ink-soft);
    padding-bottom: 0.65rem;
    border-bottom: 1px dashed rgba(61, 88, 118, 0.35);
}

.article-aside li:last-child {
    border-bottom: 0;
    padding-bottom: 0;
}

.article-nav {
    margin-top: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.55rem;
}

.article-nav a {
    border-radius: 999px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.88);
    padding: 0.4rem 0.8rem;
    font-weight: 700;
    color: var(--brand-strong);
}

.article-nav a:hover {
    border-color: rgba(255, 90, 47, 0.45);
}

.article-visual {
    background: linear-gradient(130deg, rgba(255, 212, 0, 0.3), rgba(0, 205, 182, 0.26), rgba(255, 61, 0, 0.17));
    border: 1px solid rgba(0, 205, 182, 0.38);
    border-radius: var(--radius-md);
    padding: 1.1rem;
}

.visual-subtitle {
    margin: 0.55rem 0 0;
    color: var(--ink-soft);
}

.presentation-embed {
    margin-top: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: #ffffff;
}

.presentation-embed object {
    width: 100%;
    min-height: 680px;
    display: block;
}

.presentation-embed iframe {
    width: 100%;
    height: 78vh;
    min-height: 680px;
    max-height: 980px;
    border: 0;
    display: block;
    background: #ffffff;
}

.presentation-fallback {
    padding: 1rem;
    color: var(--ink-soft);
}

.pdf-book {
    padding: 0.85rem;
    background: linear-gradient(145deg, #ffffff 0%, #eff9ff 50%, #fff9e6 100%);
}

.pdf-book-toolbar {
    display: grid;
    grid-template-columns: auto 1fr auto auto;
    align-items: center;
    gap: 0.7rem;
    margin-bottom: 0.65rem;
}

.pdf-nav-btn {
    border: 1px solid rgba(19, 36, 61, 0.16);
    border-radius: 999px;
    padding: 0.44rem 0.88rem;
    font: inherit;
    font-weight: 800;
    color: var(--brand-strong);
    background: #ffffff;
    cursor: pointer;
}

.pdf-nav-btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.pdf-page-indicator {
    margin: 0;
    text-align: center;
    font-weight: 700;
    color: var(--ink-soft);
}

.pdf-fullscreen-btn {
    white-space: nowrap;
}

.pdf-canvas-wrap {
    border: 1px solid rgba(19, 36, 61, 0.12);
    border-radius: var(--radius-sm);
    background: #eef3fa;
    min-height: 520px;
    display: grid;
    place-items: center;
    overflow: auto;
}

.pdf-canvas-wrap canvas {
    max-width: 100%;
    height: auto;
    box-shadow: 0 10px 26px rgba(16, 32, 56, 0.22);
    background: #ffffff;
}

.pdf-help,
.pdf-loading,
.pdf-error {
    margin: 0.65rem 0 0;
    color: var(--ink-soft);
    font-size: 0.9rem;
}

.pdf-error {
    color: #8c2b1f;
    font-weight: 700;
}

.pdf-error a {
    text-decoration: underline;
}

.pdf-book:fullscreen,
.pdf-book:-webkit-full-screen {
    width: 100vw;
    height: 100vh;
    max-width: none;
    margin: 0;
    padding: 1rem;
    border: 0;
    border-radius: 0;
    background: #0e1a2a;
}

.pdf-book:fullscreen .pdf-book-toolbar,
.pdf-book:-webkit-full-screen .pdf-book-toolbar {
    margin-bottom: 0.85rem;
}

.pdf-book:fullscreen .pdf-page-indicator,
.pdf-book:-webkit-full-screen .pdf-page-indicator,
.pdf-book:fullscreen .pdf-help,
.pdf-book:-webkit-full-screen .pdf-help,
.pdf-book:fullscreen .pdf-loading,
.pdf-book:-webkit-full-screen .pdf-loading {
    color: #e9f2ff;
}

.pdf-book:fullscreen .pdf-canvas-wrap,
.pdf-book:-webkit-full-screen .pdf-canvas-wrap {
    min-height: calc(100vh - 170px);
    background: #101f34;
}

.timeline {
    margin-top: 1rem;
    display: grid;
    gap: 0.75rem;
}

.timeline-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.75rem;
    align-items: start;
}

.timeline-icon {
    width: 1.95rem;
    height: 1.95rem;
    border-radius: 50%;
    display: grid;
    place-items: center;
    font-size: 0.78rem;
    font-weight: 800;
    color: #ffffff;
    background: linear-gradient(140deg, var(--brand), var(--brand-cool));
}

.timeline-content {
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem 0.88rem;
}

.timeline-content p {
    margin: 0.4rem 0 0;
}

.chat-container {
    margin-top: 1rem;
    display: grid;
    gap: 0.65rem;
}

.chat-message {
    display: flex;
}

.chat-message.user {
    justify-content: flex-end;
}

.chat-bubble {
    max-width: min(470px, 86%);
    background: #dff2ff;
    border: 1px solid #93cefb;
    border-radius: 12px;
    padding: 0.72rem 0.84rem;
    color: #1d3650;
    font-weight: 600;
}

.chat-bubble.ai {
    background: #fff0bf;
    border-color: #ffc85a;
    color: #5a3a00;
}

.feedback-wrap {
    margin-top: 2.2rem;
}

.feedback-shell {
    border: 1px solid rgba(0, 169, 157, 0.28);
    border-radius: var(--radius-lg);
    padding: 1.3rem;
    background: linear-gradient(125deg, rgba(255, 255, 255, 0.94), rgba(255, 240, 186, 0.88), rgba(221, 255, 248, 0.95), rgba(255, 216, 191, 0.8));
    box-shadow: var(--shadow-md);
}

.feedback-grid {
    display: grid;
    grid-template-columns: 0.95fr 1.05fr;
    gap: 1.1rem;
    align-items: start;
}

.feedback-copy h2 {
    margin-top: 0.7rem;
    font-size: clamp(1.35rem, 2.8vw, 2rem);
}

.feedback-copy p {
    margin: 0.8rem 0 0;
    color: var(--ink-soft);
}

.feedback-points {
    margin: 1rem 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.6rem;
}

.feedback-points li {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.55rem;
    color: var(--ink-soft);
    font-weight: 700;
}

.feedback-points li::before {
    content: '';
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    margin-top: 0.48rem;
    background: linear-gradient(140deg, var(--brand), var(--accent));
}

.feedback-form {
    border: 1px solid rgba(204, 222, 238, 0.95);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.96);
    padding: 1rem;
    box-shadow: 0 10px 20px rgba(19, 36, 61, 0.08);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.7rem;
}

.form-field {
    display: grid;
    gap: 0.4rem;
}

.form-field.full {
    grid-column: 1 / -1;
}

.form-field label {
    font-size: 0.87rem;
    font-weight: 700;
    color: var(--ink-soft);
}

.form-field input,
.form-field select,
.form-field textarea {
    width: 100%;
    border-radius: 9px;
    border: 1px solid var(--border);
    padding: 0.56rem 0.68rem;
    font: inherit;
    background: #ffffff;
    color: var(--ink);
}

.form-field textarea {
    min-height: 112px;
    resize: vertical;
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
    border-color: var(--brand-cool);
    outline: 2px solid rgba(0, 169, 157, 0.2);
    outline-offset: 0;
}

.feedback-note {
    margin: 0.6rem 0 0;
    color: var(--ink-soft);
    font-size: 0.82rem;
    font-weight: 600;
}

.feedback-status {
    margin: 0.6rem 0 0;
    min-height: 1.3rem;
    font-weight: 700;
    font-size: 0.92rem;
}

.feedback-status.success {
    color: #107a65;
}

.feedback-status.error {
    color: #b02a1a;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0;
    height: 4px;
    z-index: 30;
    background: linear-gradient(90deg, var(--brand), var(--brand-cool), var(--accent));
}

.fade-in {
    opacity: 0;
    transform: translateY(18px);
    animation: fade-up 0.6s ease forwards;
}

.delay-1 {
    animation-delay: 0.12s;
}

.delay-2 {
    animation-delay: 0.24s;
}

.delay-3 {
    animation-delay: 0.36s;
}

@keyframes fade-up {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 960px) {
    .hero-grid,
    .article-layout,
    .post-grid,
    .newsletter,
    .feedback-grid {
        grid-template-columns: 1fr;
    }

    .newsletter {
        text-align: left;
    }

    .article-aside {
        position: static;
    }

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

@media (max-width: 640px) {
    .container {
        width: min(1120px, calc(100% - 1.15rem));
    }

    .hero {
        padding-top: 3.8rem;
    }

    .article-content,
    .hero-meta,
    .newsletter,
    .topic-band,
    .feedback-shell {
        padding: 1.1rem;
    }

    .nav-wrap {
        justify-content: center;
    }

    .brand {
        width: 100%;
        text-align: center;
    }

    .nav-links {
        justify-content: center;
    }

    .chat-bubble {
        max-width: 94%;
    }
}