:root {
    --bg: #0b0f14;
    --bg-alt: #0f141b;
    --card: #121821;
    --card-2: #151d28;
    --border: #1f2933;
    --border-strong: #2b3642;

    --text: #e6edf3;
    --muted: #8b949e;
    --accent: #4fd1c5;
    --accent-hover: #38b2ac;

    --shadow: 0 10px 30px rgba(0, 0, 0, 0.24);

    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;

    --container: 1200px;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background:
        radial-gradient(circle at top right, rgba(79, 209, 197, 0.08), transparent 22%),
        linear-gradient(180deg, #0b0f14 0%, #0d1218 100%);
    color: var(--text);
    font-family: Inter, Arial, Helvetica, sans-serif;
    line-height: 1.5;
}

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

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

button {
    font: inherit;
}

.container {
    width: min(var(--container), calc(100% - 32px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(14px);
    background: rgba(11, 15, 20, 0.82);
    border-bottom: 1px solid rgba(31, 41, 51, 0.7);
}

.header-inner {
    display: flex;
    align-items: center;
    gap: 24px;
    min-height: 72px;
}

.logo {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -0.03em;
}

.logo span {
    color: var(--accent);
}

.main-nav {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 28px;
}

.main-nav a {
    color: var(--muted);
    font-size: 15px;
    transition: color 0.2s ease;
}

.main-nav a:hover {
    color: var(--text);
}

.header-cta {
    margin-left: 8px;
}

.nav-mobile-cta {
    display: none;
}

.burger {
    display: none;
    margin-left: auto;
    width: 46px;
    height: 46px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: transparent;
    color: var(--text);
    padding: 0;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.burger span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--text);
    border-radius: 99px;
    transition: 0.2s ease;
}

.burger.is-active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.burger.is-active span:nth-child(2) {
    opacity: 0;
}

.burger.is-active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 20px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 15px;
    transition:
        transform 0.2s ease,
        background 0.2s ease,
        border-color 0.2s ease,
        color 0.2s ease;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn-primary {
    background: var(--accent);
    color: #061115;
}

.btn-primary:hover {
    background: var(--accent-hover);
}

.btn-secondary {
    border: 1px solid var(--border-strong);
    background: rgba(255, 255, 255, 0.02);
    color: var(--text);
}

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--text);
}

.hero {
    padding: 64px 0 40px;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 40px;
    align-items: center;
}

.eyebrow {
    display: inline-block;
    margin-bottom: 16px;
    padding: 6px 12px;
    border: 1px solid rgba(79, 209, 197, 0.25);
    background: rgba(79, 209, 197, 0.08);
    border-radius: 999px;
    color: var(--accent);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.hero-content h1 {
    margin: 0;
    font-size: 56px;
    line-height: 1.05;
    letter-spacing: -0.04em;
    max-width: 680px;
}

.hero-text {
    margin: 24px 0 0;
    max-width: 640px;
    color: var(--muted);
    font-size: 18px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 32px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 40px;
}

.stat-card {
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
    box-shadow: var(--shadow);
}

.stat-value {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
}

.stat-label {
    margin-top: 6px;
    color: var(--muted);
    font-size: 14px;
}

.hero-visual {
    min-width: 0;
}

.hero-panel {
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background:
        linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.015)),
        radial-gradient(circle at top left, rgba(79, 209, 197, 0.10), transparent 35%);
    box-shadow: var(--shadow);
}

.hero-panel-top {
    display: flex;
    gap: 8px;
    margin-bottom: 18px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(230, 237, 243, 0.25);
}

.hardware-preview {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 16px;
}

.preview-stack {
    display: grid;
    gap: 16px;
}

.preview-card {
    min-height: 160px;
    padding: 20px;
    border: 1px solid rgba(79, 209, 197, 0.16);
    border-radius: 18px;
    background: linear-gradient(180deg, rgba(17, 24, 33, 0.95), rgba(15, 20, 27, 0.92));
}

.preview-card-large {
    min-height: 336px;
}

.preview-kicker {
    font-size: 12px;
    letter-spacing: 0.08em;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 12px;
}

.preview-card h3 {
    margin: 0 0 14px;
    font-size: 24px;
    line-height: 1.2;
}

.preview-card p {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.preview-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.preview-card li {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 12px 0;
    border-top: 1px solid rgba(255,255,255,0.06);
    color: var(--muted);
    font-size: 14px;
}

.preview-card li:first-child {
    border-top: 0;
}

.preview-card li strong {
    color: var(--text);
    font-weight: 700;
}

.section {
    padding: 48px 0;
}

.section-alt {
    background: rgba(255, 255, 255, 0.02);
    border-top: 1px solid rgba(31, 41, 51, 0.5);
    border-bottom: 1px solid rgba(31, 41, 51, 0.5);
}

.section-head {
    margin-bottom: 28px;
}

.section-head h2 {
    margin: 0;
    font-size: 34px;
    line-height: 1.15;
    letter-spacing: -0.03em;
}

.section-head p {
    margin: 10px 0 0;
    color: var(--muted);
    font-size: 16px;
}

.category-grid,
.hardware-grid,
.usecase-grid,
.guide-grid,
.footer-grid {
    display: grid;
    gap: 24px;
}

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

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

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

.guide-grid {
    grid-template-columns: repeat(3, 1fr);
}

.category-card,
.hardware-card,
.usecase-card,
.guide-card,
.cta-box {
    border: 1px solid var(--border);
    background: linear-gradient(180deg, rgba(18,24,33,0.96), rgba(16,21,29,0.96));
    border-radius: var(--radius-md);
    box-shadow: var(--shadow);
    transition:
        transform 0.2s ease,
        border-color 0.2s ease,
        box-shadow 0.2s ease;
}

.category-card:hover,
.hardware-card:hover,
.usecase-card:hover,
.guide-card:hover {
    transform: translateY(-4px);
    border-color: rgba(79, 209, 197, 0.35);
}

.category-card,
.usecase-card {
    padding: 24px;
}

.category-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 58px;
    height: 36px;
    padding: 0 12px;
    border-radius: 999px;
    background: rgba(79, 209, 197, 0.10);
    color: var(--accent);
    font-size: 13px;
    font-weight: 700;
    margin-bottom: 18px;
}

.category-card h3,
.usecase-card h3,
.guide-card h3,
.hardware-card h3 {
    margin: 0 0 10px;
    font-size: 22px;
    line-height: 1.25;
}

.category-card p,
.usecase-card p,
.guide-card p {
    margin: 0;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.65;
}

.hardware-card {
    overflow: hidden;
}

.hardware-image {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 170px;
    padding: 20px;
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--accent);
    background:
        radial-gradient(circle at top left, rgba(79, 209, 197, 0.14), transparent 30%),
        linear-gradient(180deg, #18222e 0%, #111821 100%);
    border-bottom: 1px solid var(--border);
}

.hardware-body {
    padding: 18px;
}

.badge {
    display: inline-flex;
    align-items: center;
    min-height: 28px;
    padding: 0 10px;
    margin-bottom: 14px;
    border-radius: 999px;
    background: rgba(79, 209, 197, 0.10);
    color: var(--accent);
    font-size: 12px;
    font-weight: 700;
}

.spec-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.spec-list li {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 14px;
}

.spec-list li:first-child {
    border-top: 0;
}

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

.spec-list strong {
    color: var(--text);
}

.hardware-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-top: 18px;
}

.price {
    font-size: 18px;
    font-weight: 700;
}

.text-link {
    color: var(--accent);
    font-weight: 600;
}

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

.guide-card {
    overflow: hidden;
}

.guide-image {
    min-height: 140px;
    background:
        radial-gradient(circle at top left, rgba(79, 209, 197, 0.18), transparent 28%),
        linear-gradient(135deg, #1a2330 0%, #10161f 100%);
    border-bottom: 1px solid var(--border);
}

.guide-body {
    padding: 20px;
}

.guide-body p {
    margin: 0 0 16px;
}

.cta-section {
    padding-bottom: 72px;
}

.cta-box {
    padding: 40px 24px;
    text-align: center;
    border-color: rgba(79, 209, 197, 0.25);
    background:
        radial-gradient(circle at top center, rgba(79, 209, 197, 0.10), transparent 30%),
        linear-gradient(180deg, rgba(18,24,33,0.98), rgba(15,20,27,0.98));
}

.cta-box h2 {
    margin: 0;
    font-size: 34px;
    line-height: 1.15;
}

.cta-box p {
    max-width: 760px;
    margin: 14px auto 24px;
    color: var(--muted);
    font-size: 16px;
}

.site-footer {
    border-top: 1px solid rgba(31, 41, 51, 0.7);
    padding: 36px 0 48px;
    background: rgba(0, 0, 0, 0.10);
}

.footer-grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
}

.footer-logo {
    margin-bottom: 12px;
}

.footer-text {
    max-width: 320px;
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.site-footer h4 {
    margin: 0 0 14px;
    font-size: 15px;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li + li {
    margin-top: 10px;
}

.footer-links a {
    color: var(--muted);
    font-size: 14px;
}

.footer-links a:hover {
    color: var(--text);
}

@media (max-width: 1200px) {
    .hero-content h1 {
        font-size: 48px;
    }

    .category-grid,
    .hardware-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

@media (max-width: 992px) {
    .header-cta {
        display: none;
    }

    .burger {
        display: inline-flex;
    }

    .main-nav {
        position: absolute;
        top: calc(100% + 8px);
        left: 16px;
        right: 16px;
        margin-left: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 12px;
        border: 1px solid var(--border);
        border-radius: 16px;
        background: rgba(18, 24, 33, 0.98);
        box-shadow: var(--shadow);
    }

    .main-nav.is-open {
        display: flex;
    }

    .main-nav a {
        padding: 14px 12px;
        border-radius: 10px;
    }

    .main-nav a:hover {
        background: rgba(255, 255, 255, 0.03);
    }

    .nav-mobile-cta {
        display: inline-flex;
        margin-top: 10px;
    }

    .hero {
        padding-top: 36px;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .hero-content h1 {
        font-size: 42px;
    }

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

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

    .preview-card-large {
        min-height: auto;
    }

    .usecase-grid,
    .guide-grid,
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(var(--container), calc(100% - 24px));
    }

    .site-header {
        border-bottom-color: rgba(31, 41, 51, 0.9);
    }

    .header-inner {
        min-height: 64px;
    }

    .logo {
        font-size: 21px;
    }

    .hero-content h1 {
        font-size: 34px;
        line-height: 1.08;
    }

    .hero-text {
        font-size: 16px;
        line-height: 1.65;
    }

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .section {
        padding: 36px 0;
    }

    .section-head h2,
    .cta-box h2 {
        font-size: 28px;
    }

    .category-grid,
    .hardware-grid {
        grid-template-columns: 1fr;
    }

    .category-card,
    .usecase-card,
    .guide-body,
    .hardware-body {
        padding-left: 18px;
        padding-right: 18px;
    }

    .hardware-image {
        min-height: 140px;
        font-size: 18px;
    }

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

    .cta-box {
        padding: 28px 18px;
    }
}