:root {
    --bg-dark: #07111f;
    --bg-mid: #12243d;
    --bg-soft: #eff6ff;
    --surface: rgba(246, 250, 255, 0.95);
    --surface-strong: rgba(255, 255, 255, 0.98);
    --ink: #152b45;
    --muted: #60708a;
    --line: rgba(21, 43, 69, 0.12);
    --accent: #64d2ff;
    --accent-strong: #1c74a2;
    --accent-soft: #d4f5ff;
    --warm: #ffcf65;
    --warm-strong: #b87812;
    --green: #7de6c7;
    --green-strong: #19876a;
    --shadow: 0 28px 68px rgba(6, 15, 32, 0.2);
}

* {
    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 16% 12%, rgba(100, 210, 255, 0.22), transparent 18%),
        radial-gradient(circle at 84% 18%, rgba(255, 207, 101, 0.16), transparent 18%),
        linear-gradient(180deg, #07111f 0%, #132743 18%, #eaf2fb 18.1%, #fbfdff 100%);
    min-height: 100vh;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        radial-gradient(circle at 20% 16%, rgba(255, 255, 255, 0.18) 0 1px, transparent 1.5px),
        radial-gradient(circle at 80% 12%, rgba(255, 255, 255, 0.16) 0 1px, transparent 1.6px),
        radial-gradient(circle at 72% 30%, rgba(255, 255, 255, 0.14) 0 1px, transparent 1.6px),
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 320px 320px, 280px 280px, 260px 260px, 44px 44px, 44px 44px;
    mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.82), rgba(0, 0, 0, 0.14));
}

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

button,
input {
    font: inherit;
}

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

.page-shell {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    padding-bottom: 82px;
}

.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(7, 17, 31, 0.84);
    border: 1px solid rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(18px);
    box-shadow: 0 16px 38px rgba(0, 0, 0, 0.24);
}

.brand {
    color: #f6fbff;
    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(242, 248, 255, 0.84);
    font-size: 0.95rem;
}

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

.section,
.signal-strip,
.site-footer {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity 520ms ease, transform 520ms ease;
}

.reveal.is-visible,
.site-footer.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 0.96fr) minmax(0, 1.04fr);
    gap: 24px;
    padding: 34px 0 22px;
}

.hero-copy,
.hero-panel,
.concept-card,
.formula-card,
.demo-panel,
.status-card,
.link-card,
.signal-strip,
.hero-note {
    border: 1px solid rgba(255, 255, 255, 0.68);
    background: var(--surface);
    box-shadow: var(--shadow);
    backdrop-filter: blur(14px);
}

.hero-copy {
    min-width: 0;
    padding: 42px 32px 42px 38px;
    border-radius: 38px;
    position: relative;
    overflow: hidden;
}

.hero-copy::after {
    content: "";
    position: absolute;
    inset: auto -72px -132px auto;
    width: 360px;
    height: 360px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(212, 245, 255, 0.62), rgba(212, 245, 255, 0));
}

.hero-panel {
    min-width: 0;
    padding: 26px;
    border-radius: 36px;
    display: grid;
    gap: 18px;
    background: rgba(214, 228, 244, 0.34);
}

.eyebrow,
.card-label,
.signal-kicker {
    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,
.formula-block,
.signal-main,
.canvas-caption strong {
    font-family: "Shippori Mincho", serif;
}

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

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 0;
    font-size: clamp(2.65rem, 5vw, 4.55rem);
    letter-spacing: -0.04em;
}

h2 {
    margin-bottom: 0;
    font-size: clamp(2rem, 3.8vw, 3.1rem);
    letter-spacing: -0.03em;
}

h3 {
    margin-bottom: 10px;
    font-size: 1.34rem;
}

.hero-lead,
.section-heading p,
.concept-card p,
.formula-card p,
.hero-note p,
.demo-note,
.canvas-caption,
.status-card p,
.link-card p,
.site-footer p,
.signal-sub {
    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;
    cursor: pointer;
}

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

.button-primary {
    color: #f9ffff;
    background: linear-gradient(135deg, #1d78a8, #64d2ff);
    box-shadow: 0 14px 30px rgba(28, 116, 162, 0.24);
}

.button-secondary {
    color: var(--ink);
    border-color: rgba(21, 43, 69, 0.12);
    background: rgba(255, 255, 255, 0.74);
}

.hero-points {
    list-style: none;
    padding: 0;
    margin: 26px 0 0;
    display: grid;
    gap: 12px;
}

.hero-points li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    line-height: 1.7;
}

.hero-points li::before {
    content: "";
    width: 9px;
    height: 9px;
    margin-top: 0.55em;
    border-radius: 50%;
    flex: 0 0 auto;
    background: linear-gradient(135deg, var(--accent), var(--warm));
    box-shadow: 0 0 18px rgba(100, 210, 255, 0.44);
}

.gps-window {
    position: relative;
    min-height: 318px;
    border-radius: 30px;
    overflow: hidden;
    background:
        radial-gradient(circle at 50% 24%, rgba(100, 210, 255, 0.18), transparent 18%),
        radial-gradient(circle at 76% 16%, rgba(255, 207, 101, 0.14), transparent 18%),
        linear-gradient(180deg, #07111f 0%, #0c1930 42%, #163153 100%);
    border: 1px solid rgba(255, 255, 255, 0.12);
}

.star-layer,
.orbit-ring,
.earth-disc,
.satellite,
.receiver-node,
.beam,
.clock-chip,
.measure-tag,
.continent {
    position: absolute;
}

.star-layer {
    inset: 0;
    background-image:
        radial-gradient(circle at 14% 18%, rgba(255, 255, 255, 0.82) 0 1px, transparent 1.5px),
        radial-gradient(circle at 28% 34%, rgba(255, 255, 255, 0.72) 0 1px, transparent 1.6px),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.74) 0 1px, transparent 1.6px),
        radial-gradient(circle at 72% 40%, rgba(255, 255, 255, 0.56) 0 1px, transparent 1.6px),
        linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
    background-size: auto, auto, auto, auto, 30px 30px, 30px 30px;
    opacity: 0.55;
}

.orbit-ring {
    left: 50%;
    top: 50%;
    width: 238px;
    height: 238px;
    border-radius: 50%;
    transform: translate(-50%, -46%);
    border: 1px solid rgba(100, 210, 255, 0.22);
    box-shadow: 0 0 0 18px rgba(255, 255, 255, 0.02);
}

.earth-disc {
    left: 50%;
    bottom: -64px;
    width: 238px;
    height: 238px;
    transform: translateX(-50%);
    border-radius: 50%;
    background: radial-gradient(circle at 38% 32%, #49baf1, #1e5f9c 60%, #163458 100%);
    box-shadow: 0 0 32px rgba(100, 210, 255, 0.18);
}

.continent {
    background: rgba(125, 230, 199, 0.88);
    filter: blur(0.2px);
}

.continent-a {
    width: 72px;
    height: 34px;
    left: 34px;
    top: 76px;
    border-radius: 62% 38% 54% 46% / 58% 42% 58% 42%;
    transform: rotate(-8deg);
}

.continent-b {
    width: 52px;
    height: 28px;
    right: 48px;
    top: 66px;
    border-radius: 42% 58% 60% 40% / 40% 54% 46% 60%;
    transform: rotate(16deg);
}

.continent-c {
    width: 64px;
    height: 24px;
    left: 92px;
    top: 118px;
    border-radius: 55% 45% 50% 50% / 60% 40% 60% 40%;
}

.receiver-node {
    left: 50%;
    bottom: 42px;
    width: 14px;
    height: 14px;
    transform: translateX(-50%);
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, rgba(255, 255, 255, 1), rgba(255, 207, 101, 0.2));
    box-shadow: 0 0 18px rgba(255, 207, 101, 0.54);
}

.receiver-node::before {
    content: "";
    position: absolute;
    left: 50%;
    top: -12px;
    width: 2px;
    height: 12px;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.76);
}

.receiver-node::after {
    content: "";
    position: absolute;
    inset: -10px;
    border-radius: 50%;
    border: 1px solid rgba(255, 207, 101, 0.22);
}

.satellite {
    width: 22px;
    height: 14px;
    border-radius: 6px;
    background: linear-gradient(180deg, rgba(243, 248, 255, 0.96), rgba(175, 198, 226, 0.92));
    box-shadow: 0 0 14px rgba(100, 210, 255, 0.18);
    animation: drift-satellite 10s ease-in-out infinite;
}

.satellite::before,
.satellite::after {
    content: "";
    position: absolute;
    top: 2px;
    width: 12px;
    height: 10px;
    border-radius: 2px;
    background: linear-gradient(180deg, rgba(100, 210, 255, 0.92), rgba(25, 63, 116, 0.9));
}

.satellite::before {
    left: -12px;
}

.satellite::after {
    right: -12px;
}

.sat-a {
    left: 21%;
    top: 16%;
}

.sat-b {
    right: 18%;
    top: 14%;
    animation-delay: -2.4s;
}

.sat-c {
    left: 24%;
    top: 52%;
    animation-delay: -4.2s;
}

.sat-d {
    right: 20%;
    top: 50%;
    animation-delay: -6s;
}

.beam {
    height: 2px;
    transform-origin: left center;
    background: linear-gradient(90deg, rgba(100, 210, 255, 0.9), rgba(100, 210, 255, 0));
    animation: pulse-beam 3.2s ease-in-out infinite;
}

.beam-a {
    left: 26%;
    top: 24%;
    width: 150px;
    transform: rotate(58deg);
}

.beam-b {
    right: 23%;
    top: 22%;
    width: 152px;
    transform: rotate(122deg);
    animation-delay: -0.8s;
}

.beam-c {
    left: 28%;
    top: 56%;
    width: 120px;
    transform: rotate(22deg);
    animation-delay: -1.6s;
}

.beam-d {
    right: 27%;
    top: 56%;
    width: 122px;
    transform: rotate(158deg);
    animation-delay: -2.2s;
}

.clock-chip,
.measure-tag {
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(7, 17, 31, 0.78);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: rgba(246, 251, 255, 0.9);
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.atomic-chip {
    left: 8%;
    bottom: 18%;
}

.relativity-chip {
    right: 7%;
    bottom: 20%;
}

.measure-tag {
    left: 50%;
    top: 14%;
    transform: translateX(-50%);
}

.hero-note-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
}

.hero-note,
.concept-card,
.formula-card,
.status-card,
.link-card {
    border-radius: 26px;
    padding: 22px 22px 20px;
}

.hero-note {
    min-height: 0;
}

.strong-card,
.strong-note {
    background: linear-gradient(145deg, rgba(243, 250, 255, 0.98), rgba(221, 239, 250, 0.92));
}

.warm-card,
.warm-note {
    background: linear-gradient(145deg, rgba(255, 247, 227, 0.98), rgba(255, 234, 186, 0.92));
}

.night-card,
.night-note {
    border-color: rgba(255, 255, 255, 0.12);
    background: linear-gradient(160deg, rgba(7, 16, 28, 0.97), rgba(22, 42, 69, 0.93));
}

.night-card h3,
.night-card h2,
.night-note h2,
.night-card .card-label,
.night-note .card-label,
.night-card .formula-block,
.night-note .formula-block,
.status-card.night-card h3,
.link-card.night-card h3 {
    color: rgba(245, 251, 255, 0.96);
}

.night-card p,
.night-note p,
.status-card.night-card p,
.link-card.night-card p {
    color: rgba(223, 233, 244, 0.84);
}

.signal-strip {
    position: relative;
    overflow: hidden;
    margin: 10px 0 16px;
    padding: 24px 28px;
    border-radius: 32px;
    background: linear-gradient(135deg, rgba(7, 17, 31, 0.96), rgba(18, 36, 61, 0.92));
    color: #eef8ff;
    display: grid;
    gap: 8px;
}

.signal-strip::after {
    content: "";
    position: absolute;
    inset: auto -80px -120px auto;
    width: 260px;
    height: 260px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(100, 210, 255, 0.18), rgba(100, 210, 255, 0));
}

.signal-kicker {
    margin-bottom: 2px;
    color: rgba(212, 245, 255, 0.84);
}

.signal-main {
    margin: 0;
    font-size: clamp(1.5rem, 3vw, 2.34rem);
    line-height: 1.2;
}

.signal-sub {
    margin: 0;
    color: rgba(233, 241, 251, 0.84);
    line-height: 1.8;
}

.section {
    padding: 38px 0 4px;
}

.section-heading {
    max-width: 860px;
    display: grid;
    gap: 10px;
    margin-bottom: 24px;
}

.section-heading p {
    margin-bottom: 0;
    line-height: 1.85;
}

.concept-grid,
.formula-strip,
.link-grid,
.status-panel {
    display: grid;
    gap: 16px;
}

.concept-grid,
.link-grid {
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.formula-strip {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    margin-top: 18px;
}

.formula-block {
    margin-bottom: 12px;
    font-size: clamp(1.02rem, 1.9vw, 1.34rem);
    color: var(--ink);
    line-height: 1.6;
}

.concept-card,
.link-card {
    min-height: 198px;
}

.demo-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.22fr) minmax(280px, 0.78fr);
    gap: 18px;
    align-items: start;
}

.demo-panel {
    border-radius: 32px;
    padding: 24px;
}

.mode-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 18px;
}

.mode-chip {
    min-height: 44px;
    padding: 0 18px;
    border-radius: 999px;
    border: 1px solid rgba(21, 43, 69, 0.12);
    background: rgba(255, 255, 255, 0.7);
    color: var(--ink);
    cursor: pointer;
    transition: transform 180ms ease, background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.mode-chip.is-active {
    color: #f8ffff;
    border-color: transparent;
    background: linear-gradient(135deg, #1d78a8, #64d2ff);
    box-shadow: 0 14px 30px rgba(28, 116, 162, 0.24);
}

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

.control {
    display: grid;
    gap: 10px;
    padding: 16px 18px;
    border-radius: 24px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.68);
}

.control span {
    color: var(--muted);
}

.control strong {
    color: var(--ink);
    font-size: 1.08rem;
}

.control input[type="range"] {
    width: 100%;
    accent-color: var(--accent-strong);
}

.canvas-frame {
    margin-top: 18px;
    padding: 14px;
    border-radius: 28px;
    background: linear-gradient(180deg, rgba(7, 16, 29, 0.98), rgba(15, 30, 50, 0.96));
    border: 1px solid rgba(255, 255, 255, 0.08);
}

#gpsCanvas {
    border-radius: 22px;
    background: #040b14;
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.06);
}

.canvas-caption,
.demo-note {
    margin-bottom: 0;
    line-height: 1.75;
}

.canvas-caption {
    margin-top: 14px;
}

.demo-note {
    margin-top: 12px;
}

.status-panel {
    grid-template-columns: 1fr;
}

.status-card {
    min-height: 120px;
}

.status-card h3,
.link-card h3 {
    font-size: 1.14rem;
}

.link-card {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.link-card .button {
    margin-top: auto;
}

.site-footer {
    margin-top: 38px;
    padding: 30px 32px;
    border-radius: 34px;
    background: rgba(7, 17, 31, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.22);
}

.site-footer p {
    color: rgba(233, 241, 251, 0.84);
    line-height: 1.8;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-top: 16px;
    color: rgba(233, 241, 251, 0.84);
}

.footer-links a {
    transition: color 180ms ease;
}

@keyframes drift-satellite {
    0%,
    100% {
        transform: translate3d(0, 0, 0) rotate(0deg);
    }
    50% {
        transform: translate3d(0, -6px, 0) rotate(2deg);
    }
}

@keyframes pulse-beam {
    0%,
    100% {
        opacity: 0.52;
    }
    50% {
        opacity: 0.96;
    }
}

@media (max-width: 1024px) {
    .hero,
    .demo-grid {
        grid-template-columns: 1fr;
    }

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

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

    .site-header {
        border-radius: 28px;
        padding: 16px 18px;
        align-items: flex-start;
        flex-direction: column;
    }

    .hero-copy,
    .hero-panel,
    .demo-panel,
    .site-footer {
        border-radius: 28px;
    }

    .hero-copy {
        padding: 34px 24px 34px 26px;
    }

    .hero-panel,
    .demo-panel {
        padding: 20px;
    }

    .control-grid,
    .status-panel {
        grid-template-columns: 1fr;
    }

    .mode-chip,
    .button {
        width: 100%;
    }

    .gps-window {
        min-height: 280px;
    }

    .measure-tag,
    .clock-chip {
        font-size: 0.72rem;
    }
}