/* ================= Base Reset & CSS Variables ================= */
:root {
    --bg-base: #f4f6f5;
    --bg-surface: #ffffff;
    --text-dark: #111814;
    --text-gray: #5c6660;
    --accent-green: #a7c4a0;
    --accent-green-light: #d6e5d2;
    --accent-hover: #8fb087;
    --dark-bg: #0b1c13;
    --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --font-serif: "Playfair Display", "Noto Serif SC", Georgia, serif;
    --radius-lg: 24px;
    --radius-md: 16px;
    --shadow-soft: 0 20px 40px rgba(0, 0, 0, 0.04);
    --shadow-float: 0 30px 60px rgba(11, 28, 19, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    color: var(--text-dark);
    background-color: var(--bg-base);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container { max-width: 1440px; width: 100%; margin: 0 auto; padding: 0 5vw; }

/* ================= Header / Nav ================= */
header {
    position: fixed;
    top: 0; width: 100%; height: 80px;
    background-color: rgba(244, 246, 245, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex; justify-content: space-between; align-items: center;
    padding: 0 5vw; z-index: 1000;
    border-bottom: 1px solid rgba(0,0,0,0.03);
    transition: all 0.4s ease;
}

.logo-area {
    display: flex; align-items: center; gap: 12px;
    font-size: 1.5rem; font-weight: 800; letter-spacing: -0.5px;
}
.logo-icon { width: 32px; height: 32px; fill: var(--text-dark); }

.nav-links { display: flex; gap: 3rem; }
.nav-links li a {
    font-size: 0.95rem; font-weight: 600; color: var(--text-gray);
    transition: color 0.3s;
    position: relative;
}
.nav-links li a:hover { color: var(--text-dark); }

/* Active nav link: darker text + underline indicator */
.nav-links li a.active { color: var(--text-dark); }
.nav-links li a.active::after {
    content: '';
    position: absolute;
    bottom: -4px; left: 0; right: 0;
    height: 2px;
    background: var(--dark-bg);
    border-radius: 2px;
}

.header-actions { display: flex; align-items: center; gap: 2rem; }

/* Language switcher */
.lang-switch {
    position: relative;
    font-size: 0.9rem; font-weight: 600; cursor: pointer; color: var(--text-gray);
    user-select: none;
}
.lang-current {
    display: flex; align-items: center; gap: 6px;
    padding: 6px 10px;
    border-radius: 8px;
    transition: background 0.2s, color 0.2s;
}
.lang-current:hover { background: rgba(0,0,0,0.05); color: var(--text-dark); }
.lang-short { font-size: 0.88rem; }
.lang-arrow { transition: transform 0.25s; flex-shrink: 0; }
.lang-switch.open .lang-arrow { transform: rotate(180deg); }
.lang-switch.open .lang-current { background: rgba(0,0,0,0.05); color: var(--text-dark); }

/* Language dropdown panel */
.lang-dropdown {
    position: absolute;
    top: calc(100% + 6px); right: 0;
    min-width: 158px;
    background: var(--bg-surface);
    border-radius: var(--radius-md);
    box-shadow: 0 12px 40px rgba(11,28,19,0.12), 0 2px 8px rgba(0,0,0,0.06);
    border: 1px solid rgba(0,0,0,0.06);
    overflow: hidden;
    z-index: 200;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity 0.2s, transform 0.2s, visibility 0.2s;
    pointer-events: none;
}
.lang-switch.open .lang-dropdown {
    opacity: 1; visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}
.lang-option {
    display: flex; align-items: center; gap: 10px;
    padding: 10px 14px;
    font-size: 0.9rem; font-weight: 500;
    color: var(--text-gray);
    text-decoration: none;
    transition: background 0.15s, color 0.15s;
}
.lang-option:hover { background: var(--bg-base); color: var(--text-dark); }
.lang-option--active { color: var(--text-dark); font-weight: 700; }
.lang-option .lang-flag { font-size: 1rem; flex-shrink: 0; }
.lang-option .lang-label { flex: 1; }
.lang-check { flex-shrink: 0; color: var(--dark-bg); }

.btn-primary {
    background-color: var(--dark-bg); color: #fff;
    padding: 12px 28px; border-radius: 8px; font-weight: 600; font-size: 0.95rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none; cursor: pointer;
    display: inline-flex; align-items: center; gap: 8px;
}
.btn-primary:hover {
    background-color: var(--accent-green); color: var(--dark-bg);
    transform: translateY(-2px); box-shadow: var(--shadow-float);
}

/* ================= Hero Section ================= */
.hero {
    position: relative;
    padding-top: 160px;
    padding-bottom: 120px;
    min-height: 90vh;
    display: flex;
    align-items: center;
}

.hero-bg {
    position: absolute;
    top: 0; right: 0;
    width: 65%; height: 100%;
    background: url('../../../assets/images/hero-bg.jpg') center/cover;
    mask-image: linear-gradient(to left, rgba(0,0,0,1) 40%, rgba(0,0,0,0) 100%);
    -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,1) 40%, rgba(0,0,0,0) 100%);
    z-index: -1;
    border-bottom-left-radius: 60px;
}

.hero-content {
    max-width: 700px;
    position: relative;
    z-index: 2;
}

.hero-badge {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(167, 196, 160, 0.2);
    color: var(--dark-bg);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 700;
    margin-bottom: 2rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero-title {
    font-size: clamp(3.5rem, 5vw, 5.5rem);
    line-height: 1.05;
    font-weight: 800;
    letter-spacing: -2px;
    margin-bottom: 2rem;
    color: var(--dark-bg);
}

.hero-title span {
    display: block;
    color: var(--text-gray);
    font-family: var(--font-serif);
    font-weight: 400;
    font-style: italic;
    font-size: 80%;
    margin-top: 10px;
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--text-gray);
    margin-bottom: 3.5rem;
    line-height: 1.8;
    max-width: 540px;
}

.hero-cta-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.btn-secondary {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 16px 32px; border-radius: 8px;
    font-weight: 600; font-size: 1.05rem;
    border: 1.5px solid rgba(0,0,0,0.15);
    color: var(--text-dark);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: transparent;
    cursor: pointer;
}
.btn-secondary:hover {
    border-color: var(--dark-bg);
    background: rgba(0,0,0,0.03);
}

/* Floating info card */
.hero-float-card {
    position: absolute;
    right: 5vw;
    bottom: -50px;
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255,255,255,0.8);
    border-radius: var(--radius-lg);
    padding: 40px;
    width: 400px;
    box-shadow: var(--shadow-float);
    z-index: 10;
}

.hero-float-card h3 {
    font-size: 1.5rem; margin-bottom: 15px; letter-spacing: -0.5px;
}
.hero-float-card p {
    color: var(--text-gray); font-size: 0.95rem; margin-bottom: 20px;
}

/* ================= Stats Section ================= */
.stats-section {
    padding: 120px 0 80px;
    background: var(--bg-surface);
    position: relative;
}

.stats-intro {
    max-width: 560px;
    margin-bottom: 3rem;
}
.stats-intro h2 {
    font-size: 2rem; font-weight: 800; letter-spacing: -1px;
    color: var(--dark-bg); margin-bottom: 16px;
}
.stats-intro p { font-size: 1.05rem; color: var(--text-gray); line-height: 1.8; }

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    border-top: 1px solid rgba(0,0,0,0.06);
    padding-top: 4rem;
    align-items: baseline;
}

.stat-num {
    font-size: 3.8rem; font-family: var(--font-serif); font-style: italic; font-weight: 400; color: var(--dark-bg);
    line-height: 1; margin-bottom: 12px; letter-spacing: -2px;
    padding-top: 0.08em; display: block; overflow: visible;
}
.stat-plus { vertical-align: 0.18em; font-size: 0.82em; }
.stat-label { font-size: 0.95rem; color: var(--text-gray); font-weight: 600; text-transform: uppercase; letter-spacing: 1px; }
.stat-desc { font-size: 0.88rem; color: var(--text-gray); margin-top: 8px; line-height: 1.5; opacity: 0.75; }

/* ================= Bento Features Section ================= */
.bento-section {
    padding: 100px 0 140px;
    background: var(--bg-base);
}

.section-header { margin-bottom: 80px; max-width: 600px; }
.section-header h2 {
    font-size: 3.2rem; font-weight: 800; letter-spacing: -1.5px;
    line-height: 1.15; margin-bottom: 24px; color: var(--dark-bg);
}
.section-header p { font-size: 1.15rem; color: var(--text-gray); line-height: 1.8; }

.bento-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-auto-rows: 340px;
    gap: 24px;
}

.bento-card {
    background: linear-gradient(180deg, #ffffff 0%, #fcfdfc 100%);
    border-radius: var(--radius-lg);
    padding: 48px;
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(0,0,0,0.04);
    transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.5s cubic-bezier(0.16, 1, 0.3, 1);
    display: flex; flex-direction: column;
}

.bento-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.06);
}

.bento-large {
    grid-column: span 2;
    background: linear-gradient(135deg, var(--dark-bg) 0%, #153322 100%);
    border: 1px solid rgba(255,255,255,0.08);
    color: white;
}
.bento-large .text-gray { color: rgba(255,255,255,0.65); font-weight: 300; }

.bento-vertical {
    grid-row: span 2;
    background: linear-gradient(160deg, var(--accent-green) 0%, #8fb087 100%);
    border: 1px solid rgba(255,255,255,0.3);
}

.bento-icon {
    width: 52px; height: 52px; margin-bottom: auto;
    background: var(--bg-base); border-radius: 14px;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
}
.bento-large .bento-icon { background: rgba(255,255,255,0.08); box-shadow: none; border: 1px solid rgba(255,255,255,0.1); }
.bento-vertical .bento-icon { background: rgba(255,255,255,0.3); box-shadow: none; border: 1px solid rgba(255,255,255,0.4); }

.bento-icon svg { width: 24px; height: 24px; stroke: var(--dark-bg); fill: none; stroke-width: 2; }
.bento-large .bento-icon svg { stroke: var(--accent-green); }

.bento-content { margin-top: 30px; position: relative; z-index: 2; }
.bento-title { font-size: 1.6rem; font-weight: 700; margin-bottom: 14px; letter-spacing: -0.5px; }
.bento-desc { font-size: 1.05rem; line-height: 1.7; }

/* ================= Protocol Ecosystem Section ================= */
.protocol-section {
    padding: 120px 0;
    background: var(--dark-bg);
    color: white;
    overflow: hidden;
}

.protocol-section .section-header h2 { color: white; }
.protocol-section .section-header p { color: rgba(255,255,255,0.6); }

.protocol-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 60px;
}

.protocol-card {
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: var(--radius-md);
    padding: 32px 28px;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.protocol-card:hover {
    background: rgba(167,196,160,0.1);
    border-color: rgba(167,196,160,0.4);
    transform: translateY(-6px);
}

.protocol-tag {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    margin-bottom: 14px;
}
.tag-popular { background: rgba(167,196,160,0.2); color: var(--accent-green); }
.tag-modern { background: rgba(255,200,100,0.15); color: #f5c842; }
.tag-classic { background: rgba(255,255,255,0.08); color: rgba(255,255,255,0.6); }

.protocol-name {
    font-size: 1.3rem; font-weight: 700; margin-bottom: 10px; letter-spacing: -0.3px;
}
.protocol-desc {
    font-size: 0.9rem; color: rgba(255,255,255,0.55); line-height: 1.6;
}

.protocol-footer {
    display: flex; align-items: center; gap: 16px;
    padding-top: 40px;
    border-top: 1px solid rgba(255,255,255,0.06);
}
.protocol-footer p {
    font-size: 1.05rem; color: rgba(255,255,255,0.6); line-height: 1.7;
}
.protocol-footer strong { color: white; }

/* ================= Deep Dive Section ================= */
.deep-dive-section {
    padding: 140px 0;
    background: var(--bg-surface);
    border-top: 1px solid rgba(0,0,0,0.03);
}

.deep-dive-container {
    display: flex;
    gap: 8vw;
    align-items: flex-start;
}

.deep-dive-left {
    flex: 0 0 400px;
    position: sticky;
    top: 120px;
}

.deep-dive-left h2 {
    font-size: 3rem; font-weight: 800; line-height: 1.1; margin-bottom: 30px; letter-spacing: -1.5px; color: var(--dark-bg);
}

.deep-dive-right {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 60px;
}

.dive-card {
    padding-bottom: 60px;
    border-bottom: 1px solid rgba(0,0,0,0.06);
    position: relative;
}

.dive-card::before {
    content: attr(data-step);
    position: absolute;
    top: -30px; left: -20px;
    font-size: 10rem; font-weight: 800; color: rgba(0,0,0,0.02);
    font-family: var(--font-serif); font-style: italic;
    line-height: 1; z-index: 0; pointer-events: none;
}

.dive-card h3 {
    font-size: 1.8rem; font-weight: 700; margin-bottom: 20px; letter-spacing: -0.5px; position: relative; z-index: 1; color: var(--dark-bg);
}

.dive-card p {
    font-size: 1.1rem; color: var(--text-gray); line-height: 1.8; margin-bottom: 20px; position: relative; z-index: 1;
}

.dive-card .highlight-box {
    background: var(--bg-base);
    border-left: 3px solid var(--accent-green);
    border-radius: 0 8px 8px 0;
    padding: 16px 20px;
    font-size: 1rem;
    color: var(--text-gray);
    line-height: 1.7;
    position: relative; z-index: 1;
}
.dive-card .highlight-box strong { color: var(--dark-bg); }

/* ================= Use Cases Section ================= */
.usecases-section {
    padding: 120px 0;
    background: var(--bg-base);
}

.usecases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 60px;
}

.usecase-card {
    background: var(--bg-surface);
    border-radius: var(--radius-md);
    padding: 40px 36px;
    border: 1px solid rgba(0,0,0,0.04);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.usecase-card::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-green), #6db067);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.usecase-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.06);
}

.usecase-card:hover::after { transform: scaleX(1); }

.usecase-icon {
    width: 48px; height: 48px;
    border-radius: 12px;
    background: var(--accent-green-light);
    display: flex; align-items: center; justify-content: center;
    margin-bottom: 24px;
}
.usecase-icon svg { width: 22px; height: 22px; stroke: var(--dark-bg); fill: none; stroke-width: 2; }

.usecase-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 14px; color: var(--dark-bg); }
.usecase-desc { font-size: 0.98rem; color: var(--text-gray); line-height: 1.75; }

.usecase-tags {
    display: flex; gap: 8px; flex-wrap: wrap; margin-top: 20px;
}
.usecase-tag {
    padding: 4px 10px; border-radius: 6px;
    font-size: 0.8rem; font-weight: 600;
    background: var(--bg-base); color: var(--text-gray);
    border: 1px solid rgba(0,0,0,0.06);
}

/* ================= Download Section ================= */
.download-section {
    padding: 140px 0;
    background: radial-gradient(circle at 50% 0%, #153322 0%, var(--dark-bg) 80%);
    color: white;
    text-align: center;
}

.download-header { margin-bottom: 80px; }
.download-header h2 { font-size: 4rem; font-weight: 800; letter-spacing: -1.5px; margin-bottom: 24px; }
.download-header p { font-size: 1.15rem; color: rgba(255,255,255,0.6); max-width: 560px; margin: 0 auto; line-height: 1.8; }

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 24px;
}

.platform-card {
    background: linear-gradient(145deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.01) 100%);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: var(--radius-md);
    padding: 48px 20px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    text-decoration: none;
    display: block;
}

.platform-card:hover {
    background: linear-gradient(145deg, rgba(255,255,255,0.08) 0%, rgba(255,255,255,0.02) 100%);
    border-color: rgba(167, 196, 160, 0.4);
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2), inset 0 1px 0 rgba(255,255,255,0.1);
}

.platform-card svg {
    width: 48px; height: 48px; margin-bottom: 24px; fill: var(--accent-green); transition: transform 0.4s;
}
.platform-card polyline, .platform-card line {
    fill: none;
    stroke: var(--accent-green);
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.platform-card:hover svg { transform: scale(1.1); }

.platform-name { font-weight: 700; font-size: 1.15rem; margin-bottom: 8px; letter-spacing: -0.3px; color: white; }
.platform-arch { font-size: 0.85rem; color: rgba(255,255,255,0.5); font-weight: 500; letter-spacing: 0.5px; }
.platform-clients {
    margin-top: 14px;
    font-size: 0.82rem; color: rgba(255,255,255,0.35);
    line-height: 1.5;
}

/* ================= FAQ Section ================= */
.faq-section {
    padding: 140px 0;
    background: var(--bg-surface);
}

.faq-container {
    max-width: 860px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid rgba(0,0,0,0.08);
    margin-bottom: 10px;
}

.faq-summary {
    padding: 30px 0;
    font-size: 1.25rem; font-weight: 700;
    cursor: pointer; list-style: none;
    display: flex; justify-content: space-between; align-items: center;
    color: var(--dark-bg);
    transition: color 0.3s;
    gap: 20px;
}

.faq-summary:hover { color: #3e7a39; }
.faq-summary::-webkit-details-marker { display: none; }

.faq-summary::after {
    content: '+'; font-size: 1.8rem; color: rgba(0,0,0,0.25); font-weight: 300;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    flex-shrink: 0;
}

details[open] .faq-summary::after { transform: rotate(45deg); color: var(--dark-bg); }

.faq-content {
    padding-bottom: 32px; padding-right: 40px; color: var(--text-gray); line-height: 1.85; font-size: 1.05rem;
    animation: slideDown 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ================= Footer ================= */
footer {
    background-color: var(--bg-surface);
    padding: 100px 0 40px;
    border-top: 1px solid #eaeef0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 80px;
}

.footer-brand p {
    color: var(--text-gray); margin-top: 20px; max-width: 80%; font-size: 0.95rem; line-height: 1.8;
}

.footer-col h4 { font-size: 1.1rem; font-weight: 800; margin-bottom: 24px; }
.footer-col ul li { margin-bottom: 16px; }
.footer-col ul li a { color: var(--text-gray); font-weight: 500; transition: color 0.2s; }
.footer-col ul li a:hover { color: var(--dark-bg); }

.footer-bottom {
    display: flex; justify-content: space-between; align-items: center;
    padding-top: 30px; border-top: 1px solid #eaeef0; color: var(--text-gray); font-size: 0.9rem;
}

/* ================= Mobile Navigation ================= */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px; height: 40px;
    background: none; border: none; cursor: pointer;
    padding: 6px;
    border-radius: 8px;
    transition: background 0.2s;
    flex-shrink: 0;
}
.mobile-menu-btn:hover { background: rgba(0,0,0,0.06); }
.mobile-menu-btn span {
    display: block;
    width: 22px; height: 2px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: transform 0.3s cubic-bezier(0.4,0,0.2,1), opacity 0.3s;
    transform-origin: center;
}
.mobile-menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-menu-btn.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.mobile-menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

body.mobile-menu-open { overflow: hidden; }

.mobile-nav {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 1001;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.mobile-nav.open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.mobile-nav-drawer {
    position: absolute;
    top: 0; right: 0;
    width: min(340px, 88vw);
    height: 100%;
    background: var(--bg-surface);
    display: flex; flex-direction: column;
    transform: translateX(100%);
    transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    overflow-y: auto;
    box-shadow: -8px 0 40px rgba(0,0,0,0.12);
}
.mobile-nav.open .mobile-nav-drawer { transform: translateX(0); }

.mobile-nav-top {
    display: flex; justify-content: space-between; align-items: center;
    padding: 20px 24px;
    border-bottom: 1px solid rgba(0,0,0,0.06);
    position: sticky; top: 0;
    background: var(--bg-surface);
    z-index: 1;
}

.mobile-nav-close {
    width: 36px; height: 36px;
    background: var(--bg-base); border: none; cursor: pointer;
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    color: var(--text-gray);
    transition: background 0.2s, color 0.2s;
    flex-shrink: 0;
}
.mobile-nav-close:hover { background: rgba(0,0,0,0.08); color: var(--text-dark); }

.mobile-nav-links { padding: 12px 0; }
.mobile-nav-links li a {
    display: flex; align-items: center;
    padding: 14px 24px;
    font-size: 1.05rem; font-weight: 600;
    color: var(--text-gray);
    transition: background 0.2s, color 0.2s;
    border-left: 3px solid transparent;
}
.mobile-nav-links li a:hover { background: var(--bg-base); color: var(--text-dark); }
.mobile-nav-links li a.active {
    background: var(--bg-base);
    color: var(--text-dark);
    border-left-color: var(--dark-bg);
}

.mobile-nav-lang-section {
    padding: 20px 24px;
    border-top: 1px solid rgba(0,0,0,0.06);
}
.mobile-nav-section-title {
    font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1px;
    color: var(--text-gray); margin-bottom: 12px; opacity: 0.7;
}
.mobile-nav-lang-grid {
    display: grid; grid-template-columns: 1fr 1fr; gap: 6px;
}
.mobile-nav-lang-grid .lang-option {
    border-radius: 8px;
    background: var(--bg-base);
    padding: 8px 10px;
    font-size: 0.88rem;
    border: 1px solid transparent;
    gap: 6px;
}
.mobile-nav-lang-grid .lang-option--active { border-color: rgba(0,0,0,0.1); }
.mobile-nav-lang-grid .lang-option:hover { background: rgba(0,0,0,0.05); }

.mobile-nav-footer {
    padding: 20px 24px 36px;
    margin-top: auto;
    border-top: 1px solid rgba(0,0,0,0.06);
}
.mobile-nav-cta { width: 100%; justify-content: center; }

/* On desktop: never show mobile nav elements */
@media (min-width: 769px) {
    .mobile-nav,
    .mobile-menu-btn { display: none !important; }
}

/* ================= Responsive ================= */
@media (max-width: 1200px) {
    .protocol-grid { grid-template-columns: repeat(2, 1fr); }
    .usecases-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 1024px) {
    .hero-bg { width: 100%; border-radius: 0; mask-image: none; opacity: 0.15; }
    .hero-float-card { display: none; }
    .bento-grid { grid-template-columns: 1fr 1fr; }
    .bento-large { grid-column: span 2; }
    .deep-dive-container { flex-direction: column; gap: 40px; }
    .deep-dive-left { position: static; flex: none; }
    .platforms-grid { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
}

@media (max-width: 768px) {
    .nav-links, .lang-switch { display: none; }
    .btn-primary:not(.mobile-nav-cta) { display: none; }
    .mobile-menu-btn { display: flex; }
    .hero { padding-top: 120px; text-align: center; }
    .hero-content { margin: 0 auto; }
    .hero-title { font-size: 2.8rem; }
    .hero-cta-group { justify-content: center; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
    .bento-grid { grid-template-columns: 1fr; grid-auto-rows: auto; }
    .bento-card { padding: 28px; min-height: 0; }
    .bento-icon { margin-bottom: 20px; }
    .bento-large, .bento-vertical { grid-column: span 1; grid-row: auto; }
    .protocol-grid { grid-template-columns: 1fr 1fr; }
    .usecases-grid { grid-template-columns: 1fr; }
    .platforms-grid { grid-template-columns: 1fr 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; gap: 20px; text-align: center; }
    .download-header h2 { font-size: 2.6rem; }
    .faq-summary { font-size: 1.1rem; }
}