:root {
    --ink: #10242f;
    --muted: #5f7580;
    --paper: #f7f3ea;
    --paper-strong: #fffaf0;
    --teal: #007c9a;
    --teal-deep: #00506b;
    --aqua: #29d6c8;
    --amber: #f5b544;
    --line: rgba(16, 36, 47, 0.12);
    --card: rgba(255, 255, 255, 0.78);
    --shadow: 0 24px 70px rgba(0, 65, 87, 0.18);
    --radius-xl: 34px;
    --radius-lg: 24px;
    --radius-md: 16px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
    color: var(--ink);
    background:
        radial-gradient(circle at 8% 8%, rgba(41, 214, 200, 0.22), transparent 28rem),
        radial-gradient(circle at 88% 12%, rgba(245, 181, 68, 0.20), transparent 24rem),
        linear-gradient(135deg, #eff8f7 0%, var(--paper) 52%, #edf7fb 100%);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -1;
    background-image:
        linear-gradient(rgba(0, 80, 107, 0.055) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 80, 107, 0.055) 1px, transparent 1px);
    background-size: 42px 42px;
    mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.88), transparent 82%);
}

a {
    color: var(--teal-deep);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    border-bottom: 1px solid rgba(16, 36, 47, 0.08);
    background: rgba(247, 243, 234, 0.76);
    backdrop-filter: blur(22px);
    -webkit-backdrop-filter: blur(22px);
}

.nav {
    max-width: 1180px;
    margin: 0 auto;
    padding: 14px 22px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-weight: 850;
    letter-spacing: -0.03em;
    color: var(--ink);
}

.brand img {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    box-shadow: 0 10px 26px rgba(0, 80, 107, 0.26);
}

.brand span {
    font-size: 18px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.nav-link,
.lang-btn {
    border: 1px solid transparent;
    border-radius: 999px;
    color: var(--muted);
    font: inherit;
    font-size: 14px;
    font-weight: 700;
    padding: 8px 13px;
    background: transparent;
    cursor: pointer;
}

.nav-link:hover,
.lang-btn:hover,
.lang-btn.active {
    color: var(--ink);
    text-decoration: none;
    background: rgba(255, 255, 255, 0.78);
    border-color: rgba(16, 36, 47, 0.08);
}

.lang-switch {
    display: inline-flex;
    padding: 3px;
    border-radius: 999px;
    background: rgba(16, 36, 47, 0.08);
}

.page {
    max-width: 1180px;
    margin: 0 auto;
    padding: 64px 22px 88px;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(310px, 0.95fr);
    gap: 48px;
    align-items: center;
    min-height: calc(100vh - 96px);
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin: 0 0 18px;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(0, 124, 154, 0.10);
    color: var(--teal-deep);
    font-weight: 800;
    font-size: 13px;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.eyebrow::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: var(--aqua);
    box-shadow: 0 0 0 6px rgba(41, 214, 200, 0.16);
}

h1 {
    margin: 0;
    font-size: clamp(42px, 7vw, 84px);
    line-height: 0.96;
    letter-spacing: -0.075em;
    max-width: 860px;
}

.lead {
    margin: 26px 0 0;
    max-width: 720px;
    color: var(--muted);
    font-size: clamp(18px, 2.2vw, 24px);
}

.actions {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
    margin-top: 34px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    border-radius: 999px;
    padding: 0 22px;
    font-weight: 850;
    border: 1px solid rgba(16, 36, 47, 0.12);
}

.button.primary {
    color: white;
    background: linear-gradient(135deg, var(--teal-deep), var(--teal));
    box-shadow: 0 16px 36px rgba(0, 80, 107, 0.26);
}

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

.button:hover {
    transform: translateY(-1px);
    text-decoration: none;
}

.hero-card {
    position: relative;
    padding: 22px;
    border-radius: 44px;
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.80), rgba(255, 255, 255, 0.42));
    border: 1px solid rgba(255, 255, 255, 0.66);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.hero-card::before {
    content: "";
    position: absolute;
    inset: 18px;
    border-radius: 32px;
    border: 1px solid rgba(255, 255, 255, 0.46);
    pointer-events: none;
}

.app-visual {
    position: relative;
    min-height: 540px;
    border-radius: 32px;
    overflow: hidden;
    background:
        linear-gradient(160deg, rgba(0, 80, 107, 0.92), rgba(0, 124, 154, 0.76)),
        radial-gradient(circle at 54% 36%, rgba(41, 214, 200, 0.70), transparent 16rem);
    color: white;
}

.app-visual::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.14) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.14) 1px, transparent 1px);
    background-size: 34px 34px;
    transform: perspective(440px) rotateX(54deg) translateY(96px) scale(1.1);
    transform-origin: center bottom;
    opacity: 0.66;
}

.app-icon-large {
    position: absolute;
    top: 38px;
    left: 34px;
    width: 92px;
    height: 92px;
    border-radius: 22px;
    box-shadow: 0 22px 48px rgba(0, 18, 32, 0.32);
}

.measurement-panel {
    position: absolute;
    left: 34px;
    right: 34px;
    bottom: 34px;
    padding: 22px;
    border-radius: 28px;
    background: rgba(7, 25, 35, 0.58);
    border: 1px solid rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(20px);
}

.measurement-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 13px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.measurement-row:last-child {
    border-bottom: none;
}

.measurement-row strong {
    font-size: 30px;
    letter-spacing: -0.04em;
}

.measure-tag {
    display: inline-flex;
    border-radius: 999px;
    background: rgba(41, 214, 200, 0.16);
    color: #c9fffb;
    padding: 4px 10px;
    font-size: 12px;
    font-weight: 800;
}

.ruler {
    position: absolute;
    left: 24px;
    bottom: 172px;
    width: calc(100% - 48px);
    height: 78px;
    border-left: 2px solid rgba(255, 255, 255, 0.80);
    border-bottom: 2px solid rgba(255, 255, 255, 0.80);
}

.ruler span {
    position: absolute;
    bottom: -34px;
    color: rgba(255, 255, 255, 0.72);
    font-size: 12px;
    font-weight: 800;
}

.ruler span:nth-child(1) { left: 0; }
.ruler span:nth-child(2) { left: 34%; }
.ruler span:nth-child(3) { left: 68%; }

.section {
    margin-top: 86px;
}

.section-head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 24px;
    margin-bottom: 28px;
}

h2 {
    margin: 0;
    font-size: clamp(30px, 4.8vw, 54px);
    line-height: 1.02;
    letter-spacing: -0.055em;
}

.section-head p,
.page-lead {
    color: var(--muted);
    max-width: 640px;
    margin: 0;
    font-size: 17px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.card {
    border-radius: var(--radius-lg);
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, 0.70);
    box-shadow: 0 18px 52px rgba(0, 80, 107, 0.10);
    padding: 24px;
}

.card h3 {
    margin: 0 0 10px;
    font-size: 20px;
    letter-spacing: -0.02em;
}

.card p {
    margin: 0;
    color: var(--muted);
}

.spec-list {
    display: grid;
    gap: 12px;
}

.spec {
    display: grid;
    grid-template-columns: 190px 1fr;
    gap: 16px;
    padding: 18px 0;
    border-bottom: 1px solid var(--line);
}

.spec:last-child {
    border-bottom: none;
}

.spec strong {
    color: var(--teal-deep);
}

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

.callout {
    margin-top: 22px;
    padding: 22px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, rgba(0, 124, 154, 0.12), rgba(245, 181, 68, 0.12));
    border: 1px solid rgba(0, 124, 154, 0.16);
    color: var(--ink);
}

.tutorial {
    scroll-margin-top: 96px;
}

.tutorial-stack {
    display: none;
    gap: 16px;
}

.tutorial-stack.active {
    display: grid;
}

.guide-card {
    display: grid;
    grid-template-columns: 64px 1fr;
    gap: 18px;
    padding: 24px;
    border-radius: var(--radius-lg);
    background: rgba(255, 255, 255, 0.80);
    border: 1px solid rgba(255, 255, 255, 0.74);
    box-shadow: 0 18px 52px rgba(0, 80, 107, 0.10);
}

.guide-card.warning {
    background: linear-gradient(135deg, rgba(245, 181, 68, 0.20), rgba(255, 255, 255, 0.84));
    border-color: rgba(245, 181, 68, 0.34);
}

.step-index {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 54px;
    height: 54px;
    border-radius: 18px;
    background: var(--ink);
    color: white;
    font-weight: 900;
    letter-spacing: -0.04em;
}

.guide-card h3 {
    margin: 0 0 8px;
    font-size: 22px;
    letter-spacing: -0.03em;
}

.guide-card p,
.guide-card li {
    color: var(--muted);
}

.guide-card p {
    margin: 0 0 10px;
}

.guide-card p:last-child {
    margin-bottom: 0;
}

.guide-card ol {
    margin: 0;
    padding-left: 20px;
}

.guide-card li + li {
    margin-top: 6px;
}

.document {
    max-width: 880px;
    margin: 0 auto;
}

.doc-card {
    padding: clamp(24px, 4vw, 42px);
    border-radius: var(--radius-xl);
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(255, 255, 255, 0.76);
    box-shadow: var(--shadow);
}

.doc-card h1 {
    font-size: clamp(38px, 5vw, 62px);
}

.doc-card h2 {
    margin-top: 38px;
    margin-bottom: 10px;
    font-size: 26px;
    letter-spacing: -0.03em;
}

.doc-card p,
.doc-card li {
    color: var(--muted);
}

.doc-card ul {
    padding-left: 22px;
}

.meta {
    margin: 14px 0 28px;
    color: var(--muted);
}

.two-column {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.support-item {
    padding: 20px;
    border-radius: var(--radius-md);
    background: rgba(0, 124, 154, 0.08);
    border: 1px solid rgba(0, 124, 154, 0.10);
}

.support-item h3 {
    margin: 0 0 8px;
}

.footer {
    border-top: 1px solid var(--line);
    padding: 34px 22px 48px;
    color: var(--muted);
}

.footer-inner {
    max-width: 1180px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    gap: 18px;
    flex-wrap: wrap;
}

.footer nav {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

[data-lang-panel] {
    display: none;
}

[data-lang-panel].active {
    display: block;
}

[data-lang-panel].tutorial-stack.active {
    display: grid;
}

@media (max-width: 880px) {
    .hero,
    .two-column {
        grid-template-columns: 1fr;
    }

    .hero {
        min-height: auto;
    }

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

    .section-head {
        align-items: start;
        flex-direction: column;
    }

    .spec {
        grid-template-columns: 1fr;
        gap: 4px;
    }

    .guide-card {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .nav {
        align-items: flex-start;
        flex-direction: column;
    }

    .nav-links {
        justify-content: flex-start;
    }

    .page {
        padding-top: 38px;
    }

    .app-visual {
        min-height: 460px;
    }

    .measurement-panel {
        left: 20px;
        right: 20px;
        bottom: 22px;
    }
}