/* ===== CSS Variables ===== */
:root {
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #818cf8;
    --primary-bg: #eef2ff;
    --primary-bg-dark: #e0e7ff;
    --text-dark: #1e1b4b;
    --text-body: #3730a3;
    --text-muted: #6366f1;
    --text-light: #a5b4fc;
    --bg-white: #ffffff;
    --bg-light: #f5f3ff;
    --bg-section: #faf5ff;
    --border: #e0e7ff;
    --border-light: #c7d2fe;
    --shadow-sm: 0 1px 3px rgba(79, 70, 229, 0.08);
    --shadow-md: 0 4px 16px rgba(79, 70, 229, 0.1);
    --shadow-lg: 0 8px 32px rgba(79, 70, 229, 0.12);
    --shadow-xl: 0 16px 48px rgba(79, 70, 229, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --font-sans: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', Consolas, monospace;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    color: #374151;
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

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

h1, h2, h3, h4, h5, h6 {
    color: var(--text-dark);
    line-height: 1.3;
    font-weight: 700;
}

h1 { font-size: 2.75rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.35rem; }

p {
    margin-bottom: 1rem;
    color: #4b5563;
}

ul {
    list-style: none;
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navbar ===== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 0;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}

.nav-logo {
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 700;
    font-family: var(--font-mono);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-menu li a {
    display: inline-block;
    padding: 8px 18px;
    border-radius: 999px;
    font-size: 0.95rem;
    font-weight: 500;
    color: #4b5563;
    transition: all var(--transition);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2.5px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
    padding: 80px 0 60px;
    background: linear-gradient(180deg, var(--primary-bg) 0%, var(--bg-white) 100%);
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: 6px 20px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: 0.02em;
}

.hero h1 {
    font-size: 3rem;
    max-width: 820px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--text-dark) 0%, var(--primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero h1 strong {
    -webkit-text-fill-color: var(--primary);
}

.hero-subtitle {
    font-size: 1.15rem;
    max-width: 680px;
    margin: 0 auto 32px;
    color: #6b7280;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
    max-width: 500px;
    margin: 0 auto;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    font-size: 0.9rem;
    color: #9ca3af;
    font-weight: 500;
}

/* ===== Tutorial Hero ===== */
.tutorial-hero {
    padding: 100px 0 50px;
    background: linear-gradient(180deg, var(--primary-bg) 0%, var(--bg-white) 100%);
}

.breadcrumb {
    font-size: 0.9rem;
    color: #9ca3af;
    margin-bottom: 20px;
}

.breadcrumb a {
    color: var(--primary);
}

.breadcrumb span {
    margin: 0 6px;
}

.tutorial-hero h1 {
    font-size: 2.5rem;
    max-width: 780px;
    margin-bottom: 16px;
}

.tutorial-hero h1 strong {
    color: var(--primary);
}

.tutorial-hero .hero-subtitle {
    margin: 0 0 24px;
    text-align: left;
    max-width: 700px;
}

.tutorial-meta {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    font-size: 0.9rem;
    color: #6b7280;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 999px;
    font-size: 0.95rem;
    font-weight: 600;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    border-color: var(--primary);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), #3730a3);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-2px);
}

.btn-white {
    background: #fff;
    color: var(--primary);
    border-color: #fff;
}

.btn-white:hover {
    background: var(--primary-bg);
    color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-lg {
    padding: 14px 36px;
    font-size: 1.05rem;
}

/* ===== Sections ===== */
.section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    max-width: 720px;
    margin: 0 auto 48px;
}

.section-tag {
    display: inline-block;
    padding: 4px 16px;
    background: var(--primary-bg);
    color: var(--primary);
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 16px;
    border: 1px solid var(--border);
}

.section-header h2 {
    margin-bottom: 16px;
    font-size: 2.15rem;
}

.section-header h2 strong {
    color: var(--primary);
}

.section-header p {
    font-size: 1.05rem;
    color: #6b7280;
}

/* ===== Features Grid ===== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-white);
    padding: 32px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.feature-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.feature-card p {
    font-size: 0.95rem;
    color: #6b7280;
    margin-bottom: 0;
}

/* ===== About Section ===== */
.section-about {
    background: var(--bg-light);
}

/* ===== Tutorials Grid ===== */
.tutorials-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.tutorial-card {
    background: var(--bg-white);
    padding: 32px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    position: relative;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
}

.tutorial-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.card-tag {
    display: inline-block;
    padding: 4px 12px;
    background: var(--primary-bg);
    color: var(--primary);
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 600;
    margin-bottom: 16px;
    align-self: flex-start;
    border: 1px solid var(--border);
}

.card-icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
}

.tutorial-card h3 {
    margin-bottom: 12px;
    font-size: 1.2rem;
}

.tutorial-card p {
    font-size: 0.95rem;
    color: #6b7280;
    flex-grow: 1;
}

.card-meta {
    display: flex;
    gap: 16px;
    font-size: 0.82rem;
    color: #9ca3af;
    margin-bottom: 16px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.card-link {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--primary);
    transition: all var(--transition);
}

.card-link:hover {
    color: var(--primary-dark);
    letter-spacing: 0.02em;
}

/* ===== Tips Section ===== */
.section-tips {
    background: var(--bg-light);
}

.tips-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-width: 800px;
    margin: 0 auto;
}

.tip-item {
    display: flex;
    gap: 24px;
    padding: 28px 32px;
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.tip-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.tip-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-light);
    min-width: 50px;
    font-family: var(--font-mono);
}

.tip-content h3 {
    margin-bottom: 8px;
    font-size: 1.15rem;
}

.tip-content p {
    font-size: 0.95rem;
    color: #6b7280;
    margin-bottom: 0;
}

/* ===== CTA Section ===== */
.section-cta {
    padding: 80px 0;
}

.cta-box {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 50%, #3730a3 100%);
    color: #fff;
    padding: 64px 48px;
    border-radius: var(--radius-xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 50%;
}

.cta-box::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 50%;
}

.cta-box h2 {
    color: #fff;
    margin-bottom: 16px;
    font-size: 2rem;
    position: relative;
    z-index: 1;
}

.cta-box h2 strong {
    color: #c7d2fe;
}

.cta-box p {
    color: #c7d2fe;
    max-width: 600px;
    margin: 0 auto 32px;
    font-size: 1.05rem;
    position: relative;
    z-index: 1;
}

.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

/* ===== Tutorial Content ===== */
.tutorial-content {
    padding-top: 40px;
}

.content-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

.tutorial-intro {
    margin-bottom: 48px;
}

.tutorial-intro h2 {
    margin-bottom: 20px;
    font-size: 1.85rem;
}

.tutorial-intro h2 strong {
    color: var(--primary);
}

.tutorial-section {
    margin-bottom: 48px;
}

.tutorial-section h2 {
    margin-bottom: 20px;
    font-size: 1.65rem;
}

.tutorial-section h2 strong {
    color: var(--primary);
}

/* ===== Tutorial Steps ===== */
.tutorial-step {
    margin-bottom: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--border);
}

.step-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 20px;
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 52px;
    height: 52px;
    min-width: 52px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border-radius: 50%;
    font-size: 1.35rem;
    font-weight: 800;
    font-family: var(--font-mono);
}

.step-header h2 {
    margin-bottom: 0;
    font-size: 1.5rem;
}

/* ===== Code Box ===== */
.code-box {
    background: #1e1b4b;
    border-radius: var(--radius-md);
    overflow: hidden;
    margin: 24px 0;
}

.code-box-header {
    background: rgba(255, 255, 255, 0.08);
    padding: 10px 20px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-light);
    font-family: var(--font-mono);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.code-box-content {
    padding: 20px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.8;
    color: #c7d2fe;
    overflow-x: auto;
}

.code-box-content p {
    color: #c7d2fe;
    margin-bottom: 0;
}

/* ===== Info Box ===== */
.info-box {
    background: var(--primary-bg);
    border: 1px solid var(--border);
    border-left: 4px solid var(--primary);
    border-radius: var(--radius-md);
    padding: 24px;
    margin: 24px 0;
}

.info-box-title {
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
    font-size: 1.05rem;
}

.info-box p {
    color: #4b5563;
    margin-bottom: 0;
    font-size: 0.95rem;
}

/* ===== Tip Box ===== */
.tip-box {
    background: #faf5ff;
    border: 1px solid #e9d5ff;
    border-left: 4px solid #a855f7;
    border-radius: var(--radius-md);
    padding: 24px;
    margin: 24px 0;
}

.tip-box-title {
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
    font-size: 1.05rem;
}

.tip-box p {
    color: #4b5563;
    margin-bottom: 0;
    font-size: 0.95rem;
}

/* ===== FAQ Section ===== */
.faq-section {
    padding-top: 48px;
    border-top: 1px solid var(--border);
}

.faq-item {
    padding: 24px;
    margin-bottom: 16px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.faq-question {
    color: var(--text-dark);
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.faq-answer {
    color: #4b5563;
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* ===== Tutorial CTA ===== */
.tutorial-cta {
    text-align: center;
    padding: 48px;
    background: linear-gradient(135deg, var(--primary-bg) 0%, #faf5ff 100%);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border);
    margin-top: 48px;
}

.tutorial-cta h2 {
    margin-bottom: 16px;
}

.tutorial-cta h2 strong {
    color: var(--primary);
}

.tutorial-cta p {
    max-width: 560px;
    margin: 0 auto 28px;
    color: #6b7280;
}

/* ===== Footer ===== */
.footer {
    background: #0f0a2e;
    color: #a5b4fc;
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer-logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 0.9rem;
    color: #818cf8;
    line-height: 1.7;
}

.footer-links h4 {
    color: #fff;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    color: #818cf8;
    font-size: 0.9rem;
    transition: color var(--transition);
}

.footer-links a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: #6366f1;
    margin-bottom: 0;
}

.footer-bottom a {
    color: #a5b4fc;
}

.footer-bottom a:hover {
    color: #fff;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .features-grid,
    .tutorials-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.6rem; }

    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 68px;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-md);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu li a {
        display: block;
        padding: 12px 18px;
        border-radius: var(--radius-sm);
    }

    .hero {
        padding: 60px 0 40px;
    }

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

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-stats {
        gap: 32px;
    }

    .features-grid,
    .tutorials-grid {
        grid-template-columns: 1fr;
    }

    .tip-item {
        flex-direction: column;
        gap: 12px;
        padding: 24px;
    }

    .tip-number {
        font-size: 1.5rem;
    }

    .cta-box {
        padding: 40px 24px;
    }

    .section {
        padding: 60px 0;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

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

    .tutorial-hero h1 {
        font-size: 1.85rem;
    }

    .step-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .step-number {
        width: 44px;
        height: 44px;
        min-width: 44px;
        font-size: 1.15rem;
    }

    .tutorial-cta {
        padding: 32px 24px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

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

    .hero h1 {
        font-size: 1.65rem;
    }

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

    .btn {
        width: 100%;
        text-align: center;
    }

    .hero-stats {
        gap: 24px;
        flex-wrap: wrap;
    }

    .cta-actions {
        flex-direction: column;
        align-items: center;
    }

    .tutorial-meta {
        flex-direction: column;
        gap: 8px;
    }

    .code-box-content {
        font-size: 0.8rem;
        padding: 16px;
    }

    .faq-item {
        padding: 20px;
    }
}