/* ===== CSS Reset & Variables ===== */
:root {
    --primary: #f5a623;
    --primary-hover: #e0951a;
    --primary-light: rgba(245, 166, 35, 0.15);
    --bg: #f8f9fa;
    --text: #1a1a2e;
    --card: #fff;
    --card-border: rgba(0,0,0,0.06);
    --nav-bg: rgba(26,26,46,0.95);
    --footer-bg: #1a1a2e;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 8px 32px rgba(0,0,0,0.08);
    --shadow-hover: 0 12px 40px rgba(0,0,0,0.15);
    --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --glass-bg: rgba(255,255,255,0.6);
    --glass-border: rgba(255,255,255,0.3);
    --glass-shadow: 0 8px 32px rgba(0,0,0,0.06);
    --gradient-hero: linear-gradient(135deg, #1a1a2e 0%, #16213e 40%, #0f3460 100%);
    --gradient-accent: linear-gradient(135deg, #f5a623, #f7c948);
    --max-width: 1200px;
    --nav-height: 70px;
}

[data-theme="dark"] {
    --bg: #0f0f1a;
    --text: #e0e0e0;
    --card: #1a1a2e;
    --card-border: rgba(255,255,255,0.06);
    --nav-bg: rgba(15,15,26,0.98);
    --footer-bg: #0a0a14;
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
    --shadow-hover: 0 12px 40px rgba(0,0,0,0.6);
    --glass-bg: rgba(26,26,46,0.5);
    --glass-border: rgba(255,255,255,0.08);
    --glass-shadow: 0 8px 32px rgba(0,0,0,0.3);
    --gradient-hero: linear-gradient(135deg, #0a0a14 0%, #12121e 40%, #1a1a2e 100%);
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    transition: background var(--transition), color var(--transition);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

/* ===== Navigation ===== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--nav-bg);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid rgba(255,255,255,0.06);
    height: var(--nav-height);
    transition: background var(--transition);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    text-decoration: none;
    letter-spacing: 1px;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: opacity var(--transition);
}

.logo:hover {
    opacity: 0.85;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 26px;
    height: 2.5px;
    background: var(--text);
    border-radius: 4px;
    transition: all var(--transition);
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
}

.nav-links li a {
    color: rgba(255,255,255,0.85);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all var(--transition);
    position: relative;
}

.nav-links li a::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 60%;
    height: 2px;
    background: var(--primary);
    border-radius: 2px;
    transition: transform var(--transition);
}

.nav-links li a:hover,
.nav-links li a.active {
    color: var(--primary);
    background: var(--primary-light);
}

.nav-links li a:hover::after,
.nav-links li a.active::after {
    transform: translateX(-50%) scaleX(1);
}

.dark-mode-toggle {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    color: var(--text);
    margin-left: 8px;
}

.dark-mode-toggle:hover {
    background: rgba(255,255,255,0.2);
    transform: scale(1.1);
}

/* ===== Hero Section ===== */
.hero {
    background: var(--gradient-hero);
    min-height: 85vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    overflow: hidden;
    padding: 120px 0 80px;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(245,166,35,0.08) 0%, transparent 60%),
                radial-gradient(circle at 70% 80%, rgba(15,52,96,0.2) 0%, transparent 50%);
    animation: heroGlow 12s ease-in-out infinite alternate;
    pointer-events: none;
}

@keyframes heroGlow {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(-5%, 5%) scale(1.1); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 780px;
}

.hero h1 {
    font-size: clamp(2.2rem, 6vw, 3.8rem);
    font-weight: 800;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 24px;
    text-shadow: 0 4px 30px rgba(0,0,0,0.3);
    letter-spacing: -0.5px;
}

.hero p {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: rgba(255,255,255,0.85);
    max-width: 640px;
    margin: 0 auto 36px;
    line-height: 1.8;
}

.btn-primary {
    display: inline-block;
    padding: 16px 48px;
    background: var(--gradient-accent);
    color: #1a1a2e;
    font-weight: 700;
    font-size: 1.1rem;
    border-radius: 50px;
    text-decoration: none;
    transition: all var(--transition);
    box-shadow: 0 8px 30px rgba(245,166,35,0.3);
    border: none;
    cursor: pointer;
    letter-spacing: 0.5px;
}

.btn-primary:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 40px rgba(245,166,35,0.5);
}

/* ===== Section Common ===== */
.section {
    padding: 90px 0;
}

.section h2 {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
    color: var(--text);
    position: relative;
    display: inline-block;
    width: 100%;
}

.section h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--gradient-accent);
    border-radius: 4px;
    margin: 12px auto 0;
}

.section > .container > p {
    text-align: center;
    max-width: 720px;
    margin: 0 auto 48px;
    color: var(--text);
    opacity: 0.8;
    font-size: 1.05rem;
}

/* ===== Card Grid ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 28px;
    margin-top: 40px;
}

.card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 36px 28px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    transition: all var(--transition);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}

.card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text);
}

.card p {
    color: var(--text);
    opacity: 0.8;
    line-height: 1.7;
}

.card footer {
    margin-top: 16px;
    font-style: italic;
    opacity: 0.7;
    font-size: 0.9rem;
}

blockquote.card p {
    font-style: italic;
    font-size: 1.05rem;
}

/* ===== Feature List ===== */
.feature-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 40px;
}

.feature-list li {
    background: var(--card);
    border-radius: var(--radius-sm);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    transition: all var(--transition);
    backdrop-filter: blur(8px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
}

.feature-list li:hover {
    transform: translateX(6px);
    border-color: var(--primary);
    box-shadow: var(--shadow-hover);
}

.feature-list li strong {
    color: var(--primary);
    font-weight: 700;
}

/* ===== How To List ===== */
.howto-list {
    list-style: none;
    counter-reset: step;
    max-width: 720px;
    margin: 40px auto 0;
}

.howto-list li {
    counter-increment: step;
    padding: 20px 24px 20px 60px;
    position: relative;
    background: var(--card);
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    transition: all var(--transition);
    backdrop-filter: blur(8px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
}

.howto-list li::before {
    content: counter(step);
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    background: var(--gradient-accent);
    color: #1a1a2e;
    font-weight: 800;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.howto-list li:hover {
    transform: translateX(6px);
    border-color: var(--primary);
}

.howto-list li strong {
    color: var(--primary);
}

/* ===== FAQ ===== */
.faq-list {
    max-width: 760px;
    margin: 40px auto 0;
}

.faq-list details {
    background: var(--card);
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    overflow: hidden;
    transition: all var(--transition);
    backdrop-filter: blur(8px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
}

.faq-list details[open] {
    border-color: var(--primary);
}

.faq-list summary {
    padding: 18px 24px;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background var(--transition);
    color: var(--text);
}

.faq-list summary::-webkit-details-marker {
    display: none;
}

.faq-list summary::after {
    content: '+';
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--primary);
    transition: transform var(--transition);
}

.faq-list details[open] summary::after {
    transform: rotate(45deg);
}

.faq-list summary:hover {
    background: var(--primary-light);
}

.faq-list details p {
    padding: 0 24px 20px;
    color: var(--text);
    opacity: 0.85;
    line-height: 1.7;
}

/* ===== Article List ===== */
.article-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
    margin-top: 40px;
}

.article-list li a {
    display: block;
    padding: 18px 24px;
    background: var(--card);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    color: var(--text);
    text-decoration: none;
    transition: all var(--transition);
    font-weight: 500;
    backdrop-filter: blur(8px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
}

.article-list li a:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: var(--shadow-hover);
    color: var(--primary);
}

/* ===== Contact ===== */
address {
    font-style: normal;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-top: 40px;
    background: var(--card);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(8px);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
}

address p {
    padding: 12px 0;
    border-bottom: 1px solid var(--card-border);
    display: flex;
    align-items: center;
    gap: 8px;
}

address p:last-child {
    border-bottom: none;
}

address a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

address a:hover {
    text-decoration: underline;
}

/* ===== Footer ===== */
footer {
    background: var(--footer-bg);
    color: rgba(255,255,255,0.7);
    padding: 48px 0 36px;
    margin-top: 40px;
}

.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    text-align: center;
}

.footer-inner nav {
    display: flex;
    gap: 28px;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-inner nav a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color var(--transition);
}

.footer-inner nav a:hover {
    color: var(--primary);
}

.footer-inner p:last-child {
    font-size: 0.85rem;
    opacity: 0.6;
    max-width: 600px;
}

/* ===== Back to Top ===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--gradient-accent);
    color: #1a1a2e;
    border: none;
    border-radius: 50%;
    font-size: 1.4rem;
    cursor: pointer;
    display: none;
    z-index: 999;
    box-shadow: 0 4px 20px rgba(245,166,35,0.3);
    transition: all var(--transition);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(245,166,35,0.5);
}

/* ===== Scroll Animations ===== */
.section {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 0.8s ease forwards;
}

.section:nth-child(2) { animation-delay: 0.1s; }
.section:nth-child(3) { animation-delay: 0.2s; }
.section:nth-child(4) { animation-delay: 0.3s; }
.section:nth-child(5) { animation-delay: 0.4s; }
.section:nth-child(6) { animation-delay: 0.5s; }
.section:nth-child(7) { animation-delay: 0.6s; }
.section:nth-child(8) { animation-delay: 0.7s; }
.section:nth-child(9) { animation-delay: 0.8s; }
.section:nth-child(10) { animation-delay: 0.9s; }

@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Responsive ===== */
@media (max-width: 992px) {
    .section {
        padding: 70px 0;
    }
    
    .hero {
        min-height: 70vh;
        padding: 100px 0 60px;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--nav-bg);
        backdrop-filter: blur(30px);
        -webkit-backdrop-filter: blur(30px);
        flex-direction: column;
        padding: 80px 24px 40px;
        gap: 8px;
        transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: -10px 0 40px rgba(0,0,0,0.2);
        z-index: 999;
    }

    .nav-links.open {
        right: 0;
    }

    .nav-links li a {
        font-size: 1.1rem;
        padding: 12px 20px;
        width: 100%;
        text-align: left;
    }

    .dark-mode-toggle {
        margin-left: 0;
        margin-top: 8px;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

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

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

    address {
        grid-template-columns: 1fr;
        padding: 24px;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 42px;
        height: 42px;
        font-size: 1.2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero {
        padding: 80px 0 40px;
    }

    .section {
        padding: 50px 0;
    }

    .card {
        padding: 24px 20px;
    }

    .howto-list li {
        padding: 16px 16px 16px 52px;
    }

    .howto-list li::before {
        width: 28px;
        height: 28px;
        font-size: 0.8rem;
        left: 12px;
    }
}