:root {
    --bg: #FAFAF8;
    --surface: #FFFFFF;
    --border: #E8E6E1;
    --border-hover: #D4D1CA;
    --text-primary: #1A1917;
    --text-secondary: #6B6860;
    --text-tertiary: #9C9890;
    --accent: #2563EB;
    --accent-soft: #EFF6FF;
    --accent-hover: #1D4ED8;
    --success: #059669;
    --success-soft: #ECFDF5;
    --error: #DC2626;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px rgba(26, 25, 23, 0.04);
    --shadow-md: 0 4px 12px rgba(26, 25, 23, 0.06);
    --shadow-lg: 0 8px 30px rgba(26, 25, 23, 0.08);
    --font-display: 'Outfit', sans-serif;
    --font-body: 'Karla', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
}

.noise-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.018;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(250, 250, 248, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-mark {
    color: var(--accent);
    display: flex;
}

.logo-text {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.1rem;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 6px 14px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.nav-link:hover {
    color: var(--text-primary);
    background: rgba(26, 25, 23, 0.04);
}

/* Hero */
.hero {
    padding: 80px 0 60px;
    text-align: center;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 12px;
    animation: fadeUp 0.6s ease both;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    animation: fadeUp 0.6s ease 0.1s both;
}

/* Converter */
.converter {
    max-width: 640px;
    margin: 0 auto;
    animation: fadeUp 0.6s ease 0.2s both;
}

.converter-input-wrap {
    display: flex;
    gap: 10px;
    background: var(--surface);
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    padding: 6px 6px 6px 20px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.converter-input-wrap:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.converter-input {
    flex: 1;
    border: none;
    outline: none;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-primary);
    background: transparent;
}

.converter-input::placeholder {
    color: var(--text-tertiary);
}

.convert-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.convert-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.convert-btn:active {
    transform: translateY(0);
}

.btn-arrow {
    transition: transform 0.2s ease;
}

.convert-btn:hover .btn-arrow {
    transform: translateX(2px);
}

/* Result */
.result-box {
    margin-top: 16px;
    background: var(--success-soft);
    border: 1px solid #A7F3D0;
    border-radius: var(--radius-sm);
    padding: 14px 18px;
    text-align: left;
    animation: fadeUp 0.3s ease both;
}

.result-box.hidden {
    display: none;
}

.result-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--success);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 6px;
}

.result-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.result-url {
    flex: 1;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-primary);
    word-break: break-all;
    line-height: 1.5;
}

.copy-btn {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--surface);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.copy-btn:hover {
    border-color: var(--success);
    color: var(--success);
}

.copy-btn.copied {
    border-color: var(--success);
    color: var(--success);
    background: var(--success-soft);
}

/* Usage Section */
.usage-section {
    padding: 60px 0;
}

.section-title {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 28px;
}

.usage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
    gap: 16px;
}

@media (max-width: 520px) {
    .usage-grid {
        grid-template-columns: 1fr;
    }
}

.usage-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: all 0.25s ease;
}

.usage-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    background: var(--accent-soft);
    color: var(--accent);
    margin-bottom: 14px;
}

.usage-card h3 {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.usage-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 14px;
}

.code-block {
    position: relative;
    background: #F8F7F5;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 14px;
    overflow-x: auto;
}

.code-block code {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-primary);
    white-space: nowrap;
}

.code-block .domain {
    color: var(--accent);
    font-weight: 500;
}

.code-copy {
    position: absolute;
    top: 8px;
    right: 8px;
    padding: 3px 10px;
    font-size: 0.7rem;
    font-family: var(--font-body);
    font-weight: 500;
    color: var(--text-tertiary);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.code-copy:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.code-copy.copied {
    color: var(--success);
    border-color: var(--success);
}

.tip-box {
    margin-top: 24px;
    padding: 14px 18px;
    background: var(--accent-soft);
    border: 1px solid #BFDBFE;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.tip-box code {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    background: rgba(37, 99, 235, 0.08);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--accent);
}

/* Stats Section */
.stats-section {
    padding: 60px 0 80px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    text-align: center;
    transition: all 0.25s ease;
}

.stat-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-sm);
}

.stat-value {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    font-weight: 500;
}

/* Chart */
.chart-wrap {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
}

.chart-title {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.chart {
    display: flex;
    align-items: flex-end;
    gap: 4px;
    height: 120px;
}

.chart-bar-wrap {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    height: 100%;
    justify-content: flex-end;
    gap: 6px;
}

.chart-bar {
    width: 100%;
    max-width: 28px;
    background: var(--accent-soft);
    border-radius: 4px 4px 2px 2px;
    transition: all 0.3s ease;
    min-height: 3px;
}

.chart-bar:hover {
    background: var(--accent);
}

.chart-bar-label {
    font-size: 0.6rem;
    color: var(--text-tertiary);
    font-family: var(--font-mono);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 24px 0;
    text-align: center;
}

.site-footer p {
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

/* Animations */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 640px) {
    .hero {
        padding: 50px 0 40px;
    }

    .converter-input-wrap {
        flex-direction: column;
        padding: 12px;
    }

    .convert-btn {
        justify-content: center;
    }

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

    .nav-links {
        display: none;
    }
}

.hidden {
    display: none !important;
}