:root {
    --bg-dark: #111f28;
    --bg-mid: #21495a;
    --surface: rgba(252, 247, 239, 0.9);
    --surface-soft: rgba(241, 247, 250, 0.84);
    --surface-strong: rgba(255, 252, 246, 0.96);
    --ink: #1f2a33;
    --muted: #64717c;
    --line: rgba(31, 42, 51, 0.12);
    --accent: #285f73;
    --accent-strong: #183f4d;
    --accent-soft: #d48d49;
    --accent-soft-strong: #a4611f;
    --shadow: 0 28px 64px rgba(17, 31, 40, 0.18);
    --radius: 30px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--ink);
    font-family: "IBM Plex Sans JP", sans-serif;
    background:
        radial-gradient(circle at 12% 16%, rgba(212, 141, 73, 0.24), transparent 22%),
        radial-gradient(circle at 84% 12%, rgba(40, 95, 115, 0.28), transparent 18%),
        linear-gradient(180deg, #101c24 0%, #1c3f4f 18%, #efe6da 18.1%, #f7f2ea 100%);
    min-height: 100vh;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
    background-size: 44px 44px;
    mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.72), rgba(0, 0, 0, 0.08));
}

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

button,
input {
    font: inherit;
}

.page-shell {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    padding-bottom: 80px;
}

.site-header {
    position: sticky;
    top: 14px;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin: 18px 0 20px;
    padding: 16px 22px;
    border-radius: 999px;
    background: rgba(16, 28, 36, 0.74);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(18px);
    box-shadow: 0 16px 38px rgba(0, 0, 0, 0.18);
}

.brand {
    color: #f8efe1;
    font-family: "Shippori Mincho", serif;
    font-size: 1.14rem;
    letter-spacing: 0.1em;
}

.site-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 18px;
    color: rgba(248, 239, 225, 0.84);
    font-size: 0.95rem;
}

.site-nav a:hover,
.site-nav a:focus-visible,
.footer-link:hover,
.footer-link:focus-visible {
    color: white;
}

.section,
.signal-strip,
.site-footer {
    opacity: 1;
    transform: none;
    transition: none;
}

.reveal.is-visible,
.site-footer.is-visible {
    opacity: 1;
    transform: none;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 0.94fr) minmax(0, 1.06fr);
    gap: 22px;
    padding: 34px 0 22px;
}

.hero-copy,
.hero-panel,
.point-card,
.panel-card,
.limit-card,
.value-card,
.error-card,
.demo-panel,
.visual-panel,
.evaluation-card,
.trust-card,
.closing-card,
.table-card,
.signal-strip {
    border: 1px solid rgba(255, 255, 255, 0.6);
    background: var(--surface);
    box-shadow: var(--shadow);
    backdrop-filter: blur(14px);
}

.hero-copy {
    min-width: 0;
    padding: 40px 30px 40px 36px;
    border-radius: 38px;
    position: relative;
    overflow: hidden;
}

.hero-copy::after {
    content: "";
    position: absolute;
    inset: auto -44px -88px auto;
    width: 280px;
    height: 280px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(212, 141, 73, 0.52), rgba(212, 141, 73, 0));
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--accent-strong);
    font-size: 0.84rem;
    font-weight: 700;
    letter-spacing: 0.22em;
    text-transform: uppercase;
}

h1,
h2,
h3,
.brand {
    line-height: 1.15;
}

h1,
h2 {
    margin: 0;
    font-family: "Shippori Mincho", serif;
}

h1 {
    font-size: clamp(2.55rem, 5vw, 4.7rem);
    letter-spacing: -0.04em;
}

.hero-lead,
.section-heading p,
.model-step p,
.hero-note p,
.hero-summary p,
.point-card p,
.panel-card p,
.limit-card p,
.value-card p,
.error-card p,
.demo-note,
.equation-panel p,
.convergence-caption,
.evaluation-card p,
.trust-card p,
.site-footer p,
.signal-sub,
.comparison-table td,
.comparison-table th {
    color: var(--muted);
}

.hero-lead {
    margin: 20px 0 0;
    font-size: 1.04rem;
    line-height: 1.85;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 28px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 52px;
    padding: 0 22px;
    border-radius: 999px;
    border: 1px solid transparent;
    transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover,
.button:focus-visible {
    transform: translateY(-2px);
}

.button-primary {
    color: white;
    background: linear-gradient(135deg, var(--accent), var(--accent-strong));
    box-shadow: 0 14px 28px rgba(24, 63, 77, 0.28);
}

.button-secondary {
    background: rgba(255, 255, 255, 0.72);
    border-color: var(--line);
}

.hero-points {
    margin: 24px 0 0;
    padding-left: 1.2rem;
    display: grid;
    gap: 10px;
    position: relative;
    z-index: 1;
}

.hero-panel {
    min-width: 0;
    padding: 26px;
    border-radius: 36px;
    display: grid;
    gap: 18px;
    background: rgba(247, 252, 252, 0.18);
}

.model-board {
    display: flex;
    gap: 12px;
    align-items: stretch;
}

.model-step,
.hero-note,
.hero-summary {
    padding: 20px 22px;
    border-radius: 24px;
    background: linear-gradient(145deg, rgba(255, 249, 241, 0.96), rgba(241, 247, 250, 0.82));
    border: 1px solid rgba(31, 42, 51, 0.08);
}

.model-step {
    flex: 1 1 0;
    min-width: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 128px;
    padding: 28px 30px;
    text-align: center;
    box-shadow: 0 16px 32px rgba(17, 31, 40, 0.08);
}

.model-step span,
.card-label,
.note-label,
.summary-title,
.signal-kicker,
.convergence-item span {
    display: inline-block;
    font-weight: 700;
    color: var(--accent-strong);
    letter-spacing: 0.08em;
}

.model-step strong,
.hero-note h2,
.point-card h3,
.panel-card h3,
.limit-card h3,
.value-card h3,
.error-card h3,
.evaluation-card h3,
.trust-card h3,
.closing-title,
.signal-main,
.hero-summary p strong {
    font-family: "Shippori Mincho", serif;
}

.model-step strong {
    display: block;
    margin-top: 8px;
    font-size: 1.38rem;
}

.model-step p,
.hero-note p,
.hero-summary p {
    margin: 10px 0 0;
}

.model-arrow {
    flex: 0 0 72px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-width: 72px;
    padding: 16px 10px 14px;
    border-radius: 22px;
    background: linear-gradient(160deg, rgba(24, 63, 77, 0.96), rgba(40, 95, 115, 0.92));
    color: rgba(255, 255, 255, 0.96);
    font-size: 0.92rem;
    line-height: 1.25;
    font-weight: 700;
    white-space: nowrap;
    box-shadow: 0 18px 36px rgba(24, 63, 77, 0.22);
}

.model-arrow::before {
    content: "";
    width: 34px;
    height: 16px;
    background: currentColor;
    clip-path: polygon(0 38%, 68% 38%, 68% 0, 100% 50%, 68% 100%, 68% 62%, 0 62%);
}

.reality-step {
    background: linear-gradient(145deg, rgba(240, 247, 255, 0.98), rgba(225, 236, 249, 0.88));
}

.model-step-accent,
.strong-card {
    background: linear-gradient(145deg, rgba(241, 248, 250, 0.98), rgba(226, 239, 244, 0.88));
}

.output-step,
.warm-card {
    background: linear-gradient(145deg, rgba(255, 248, 236, 0.98), rgba(247, 234, 214, 0.88));
}

.hero-note-grid,
.difference-grid,
.essence-grid,
.limits-grid,
.value-grid,
.error-grid,
.demo-grid,
.evaluation-grid,
.trust-grid {
    display: grid;
    gap: 20px;
}

.hero-note-grid,
.difference-grid,
.trust-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.hero-note,
.hero-summary,
.point-card,
.panel-card,
.limit-card,
.value-card,
.error-card,
.demo-panel,
.visual-panel,
.evaluation-card,
.trust-card,
.closing-card,
.table-card {
    padding: 24px 26px;
    border-radius: 28px;
}

.hero-summary {
    background: linear-gradient(145deg, rgba(24, 63, 77, 0.98), rgba(40, 95, 115, 0.94));
    color: white;
}

.hero-summary p,
.hero-summary .summary-title {
    color: white;
    margin: 0;
}

.hero-summary p:last-child {
    margin-top: 10px;
}

.signal-strip {
    margin-top: 10px;
    padding: 24px 30px;
    border-radius: 30px;
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr) minmax(0, 1fr);
    gap: 18px;
    align-items: center;
}

.signal-kicker {
    margin: 0;
    font-size: 0.86rem;
    text-transform: uppercase;
}

.signal-main {
    font-size: clamp(1.65rem, 3vw, 2.4rem);
    margin: 0;
}

.signal-sub {
    margin: 0;
    line-height: 1.75;
}

.section {
    margin-top: 88px;
}

.section-heading {
    margin-bottom: 26px;
}

.section-heading h2 {
    font-size: clamp(2rem, 3.5vw, 3.1rem);
}

.section-heading p {
    margin: 12px 0 0;
    max-width: 820px;
    line-height: 1.85;
}

.table-card {
    overflow: hidden;
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
}

.comparison-table th,
.comparison-table td {
    padding: 16px 18px;
    border-bottom: 1px solid rgba(31, 42, 51, 0.08);
    text-align: left;
}

.comparison-table th {
    color: var(--ink);
    background: rgba(24, 63, 77, 0.08);
}

.essence-grid,
.limits-grid,
.value-grid,
.error-grid,
.evaluation-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.demo-grid {
    grid-template-columns: minmax(0, 1fr) minmax(320px, 0.95fr);
}

.demo-panel,
.visual-panel {
    background: linear-gradient(180deg, rgba(252, 247, 239, 0.96), rgba(241, 247, 250, 0.86));
}

.control {
    display: grid;
    gap: 8px;
    margin-bottom: 18px;
}

.control span {
    color: var(--accent-strong);
    font-weight: 600;
}

.control input {
    width: 100%;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    margin-top: 18px;
}

.stat-grid article,
.equation-panel,
.convergence-board,
.convergence-item {
    padding: 18px 20px;
    border-radius: 22px;
    background: rgba(255, 255, 255, 0.74);
    border: 1px solid rgba(31, 42, 51, 0.08);
}

.stat-grid span,
.convergence-title {
    color: var(--muted);
    font-size: 0.9rem;
}

.stat-grid strong,
.equation-block,
.convergence-item strong {
    display: block;
    margin-top: 8px;
}

.demo-note {
    margin: 18px 0 0;
    line-height: 1.8;
}

.equation-panel {
    margin-bottom: 16px;
}

.equation-block {
    font-family: "Shippori Mincho", serif;
    font-size: clamp(1.1rem, 2vw, 1.6rem);
    color: var(--ink);
}

.inline-equation {
    white-space: nowrap;
}

.convergence-title {
    margin: 0;
}

.convergence-grid {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.convergence-item {
    display: grid;
    grid-template-columns: 92px 1fr auto;
    gap: 12px;
    align-items: center;
}

.convergence-item.is-current {
    border-color: rgba(40, 95, 115, 0.3);
    background: rgba(40, 95, 115, 0.08);
}

.convergence-bar {
    height: 12px;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--accent-soft), var(--accent));
}

.convergence-caption {
    margin: 16px 0 0;
    line-height: 1.75;
}

.closing-card {
    margin-top: 22px;
    background: linear-gradient(135deg, rgba(212, 141, 73, 0.98), rgba(164, 97, 31, 0.92));
    color: white;
    border-color: rgba(255, 255, 255, 0.16);
}

.closing-title,
.closing-copy {
    margin: 0;
    font-family: "Shippori Mincho", serif;
}

.closing-title {
    color: rgba(255, 255, 255, 0.82);
}

.closing-copy {
    margin-top: 10px;
    color: white;
    font-size: clamp(1.2rem, 2vw, 1.7rem);
    line-height: 1.7;
}

.site-footer {
    margin-top: 64px;
    padding: 24px 30px;
    border-radius: 28px;
    background: rgba(16, 28, 36, 0.86);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.82);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.site-footer p {
    margin: 0;
}

.footer-links {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
}

.footer-link {
    color: white;
    font-weight: 600;
}

@media (max-width: 1080px) {
    .hero,
    .signal-strip,
    .demo-grid,
    .difference-grid,
    .trust-grid {
        grid-template-columns: 1fr;
    }

    .essence-grid,
    .limits-grid,
    .value-grid,
    .error-grid,
    .evaluation-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .signal-strip {
        gap: 10px;
    }
}

@media (max-width: 760px) {
    .page-shell {
        width: min(100% - 20px, 1200px);
    }

    .site-header {
        position: static;
        flex-direction: column;
        align-items: flex-start;
        border-radius: 28px;
    }

    .site-nav {
        justify-content: flex-start;
        gap: 12px 14px;
    }

    .hero-copy,
    .hero-panel,
    .point-card,
    .panel-card,
    .limit-card,
    .value-card,
    .error-card,
    .demo-panel,
    .visual-panel,
    .evaluation-card,
    .trust-card,
    .closing-card,
    .table-card,
    .signal-strip,
    .site-footer,
    .hero-note,
    .hero-summary {
        padding: 22px;
        border-radius: 24px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .button {
        width: 100%;
    }

    .model-board,
    .hero-note-grid,
    .essence-grid,
    .limits-grid,
    .value-grid,
    .error-grid,
    .evaluation-grid,
    .stat-grid {
        grid-template-columns: 1fr;
    }

    .model-arrow {
        width: min(100%, 160px);
        justify-self: center;
        align-self: center;
        justify-self: center;
    }

    .model-board {
        flex-direction: column;
    }

    .model-arrow::before {
        transform: rotate(90deg);
    }

    .convergence-item {
        grid-template-columns: 1fr;
    }

    .hero,
    .section {
        margin-top: 68px;
    }

    .site-footer {
        flex-direction: column;
        align-items: flex-start;
    }
}