:root {
    --bg-color: #f5f5f7;
    --text-color: #1d1d1f;
    --btn-bg: #4CAF50;
    --number-bg: #e8e8ed;
    --number-text: #1d1d1f;
    --card-bg: #ffffff;
    --border-color: #d2d2d7;
    --muted: #6e6e73;
    --nav-bg: rgba(255,255,255,0.85);
}

[data-theme="dark"] {
    --bg-color: #1a1a2e;
    --text-color: #e0e0e0;
    --btn-bg: #16a34a;
    --number-bg: #2d2d44;
    --number-text: #e0e0e0;
    --card-bg: #22223a;
    --border-color: #3a3a52;
    --muted: #9999aa;
    --nav-bg: rgba(26,26,46,0.9);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.7;
    transition: background-color 0.3s, color 0.3s;
}

/* Navigation */
.main-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
}

.nav-inner {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-logo {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-color);
    text-decoration: none;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 24px;
}

.nav-links a {
    text-decoration: none;
    color: var(--muted);
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-color);
}

#theme-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    font-size: 18px;
    cursor: pointer;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: border-color 0.3s, background 0.3s;
}

/* Main */
main {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Hero */
.hero {
    text-align: center;
    padding: 60px 0 40px;
}

.hero h1 {
    font-size: 28px;
    margin-bottom: 12px;
}

.hero-desc {
    color: var(--muted);
    font-size: 15px;
    margin-bottom: 30px;
}

#generator-btn {
    padding: 14px 36px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    background-color: var(--btn-bg);
    color: white;
    border: none;
    border-radius: 10px;
    margin-bottom: 24px;
    transition: opacity 0.2s;
}

#generator-btn:hover { opacity: 0.9; }

#numbers-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    min-height: 50px;
}

.number {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--number-bg);
    color: var(--number-text);
    transition: background-color 0.3s, color 0.3s;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 18px;
    font-weight: bold;
}

/* History */
#history-section {
    margin-top: 24px;
}

#history-section h3 {
    font-size: 15px;
    color: var(--muted);
    margin-bottom: 10px;
}

#history-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

#history-list li {
    font-size: 14px;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
}

/* Content Sections */
.content-section {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 32px;
    margin: 30px 0;
    transition: background 0.3s, border-color 0.3s;
}

.content-section h2 {
    font-size: 22px;
    margin-bottom: 16px;
}

.content-section h3 {
    font-size: 17px;
    margin: 20px 0 10px;
}

.content-section p {
    color: var(--muted);
    font-size: 15px;
    margin-bottom: 12px;
}

/* Table */
.info-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 12px;
    font-size: 14px;
}

.info-table th,
.info-table td {
    padding: 10px 14px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.info-table th {
    font-weight: 600;
    font-size: 13px;
    color: var(--muted);
    text-transform: uppercase;
}

/* Steps */
.steps {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.step-num {
    width: 32px;
    height: 32px;
    min-width: 32px;
    border-radius: 50%;
    background: var(--btn-bg);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
    margin-top: 2px;
}

.step h3 { margin: 0 0 4px; }
.step p { margin: 0; }

/* FAQ */
.faq {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.faq details {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px 18px;
    transition: border-color 0.3s;
}

.faq summary {
    cursor: pointer;
    font-weight: 600;
    font-size: 15px;
}

.faq details p {
    margin-top: 10px;
    margin-bottom: 0;
}

/* Disqus */
.disqus-wrapper {
    margin: 40px 0;
}

.disqus-title {
    text-align: center;
    margin-bottom: 20px;
    font-size: 22px;
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--border-color);
    margin-top: 40px;
    padding: 30px 20px;
    text-align: center;
}

.footer-inner {
    max-width: 900px;
    margin: 0 auto;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
    margin-bottom: 14px;
}

.footer-links a {
    color: var(--muted);
    text-decoration: none;
    font-size: 13px;
}

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

.footer-copy {
    font-size: 12px;
    color: var(--muted);
}

/* Page layout for sub pages */
.page-content {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px 60px;
}

.page-content h1 {
    font-size: 28px;
    margin-bottom: 20px;
}

.page-content h2 {
    font-size: 20px;
    margin: 30px 0 12px;
}

.page-content p,
.page-content li {
    color: var(--muted);
    font-size: 15px;
    margin-bottom: 10px;
}

.page-content ul,
.page-content ol {
    padding-left: 24px;
}

/* Contact page overrides */
.contact-container {
    max-width: 500px;
    width: 100%;
    padding: 40px 20px 60px;
    margin: 0 auto;
}

.subtitle {
    margin-bottom: 30px;
    color: var(--muted);
    font-size: 14px;
}

.form-group {
    margin-bottom: 18px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    font-weight: 600;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 12px;
    font-size: 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--card-bg);
    color: var(--text-color);
    transition: border-color 0.3s, background-color 0.3s, color 0.3s;
    box-sizing: border-box;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--btn-bg);
}

.form-group textarea { resize: vertical; }

#submit-btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    background-color: var(--btn-bg);
    color: white;
    border: none;
    border-radius: 8px;
    margin-top: 8px;
    transition: opacity 0.2s;
}

#submit-btn:hover { opacity: 0.9; }
#submit-btn:disabled { opacity: 0.6; cursor: not-allowed; }

.back-link {
    display: inline-block;
    margin-top: 20px;
    color: var(--muted);
    font-size: 14px;
    text-decoration: none;
}

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

.hidden { display: none !important; }

#success-message {
    padding: 40px 0;
    font-size: 16px;
    text-align: center;
}

/* Responsive */
@media (max-width: 600px) {
    .nav-links { gap: 14px; }
    .nav-links a { font-size: 12px; }
    .hero h1 { font-size: 22px; }
    .content-section { padding: 24px 18px; }
    .footer-links { gap: 16px; }
}