:root {
    --primary: #4e52f8;
    --primary-hover: #3b3fd4;
    --dark: #0f172a;
    --light: #fff;
    --dark-bg: #1c1e22;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --success: #10b981;
    --success-bg: #d1fae5;
    --error: #ef4444;
    --error-bg: #fee2e2;
    --border-radius: 12px;
    --transition: all 0.2s ease;
    --text-color: #0f172a;
    --bg-color: #f8fafc;
    --card-bg: #fff;
    --border-color: #e2e8f0;
}

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

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
    --text-color: #e4e4e7;
    --bg-color: #1c1e22;
    --card-bg: #27292d;
    --light: #27292d;
    --border-color: #3a3c40;
    --gray-50: #27292d;
    --gray-100: #2d2f33;
    --gray-200: #3a3c40;
    --success-bg: #064e3b;
    --error-bg: #7f1d1d;
}

a {
    color: inherit;
    text-decoration: none;
}

/* Header */
.ai-header {
    background: var(--light);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.ai-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.ai-logo {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 10px;
    transition: var(--transition);
}

.ai-logo:hover {
    color: var(--primary);
}

.ai-logo-icon {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--primary), #7c3aed);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--light);
    font-size: 18px;
}

.ai-header-right {
    display: flex;
    align-items: center;
    gap: 30px;
}

.ai-global-nav {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.ai-tab {
    padding: 10px 18px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-color);
    background: transparent;
    transition: var(--transition);
    border: 1px solid transparent;
}

.ai-tab:hover {
    background: var(--gray-100);
    color: var(--text-color);
}

.ai-tab.active {
    background: var(--primary);
    color: var(--light);
    border-color: var(--primary);
}

/* Theme Toggle Switch */
.theme-toggle {
    position: relative;
    display: inline-block;
    width: 52px;
    height: 28px;
    cursor: pointer;
    flex-shrink: 0;
}

.theme-toggle input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: #cbd5e1;
    border-radius: 28px;
    transition: 0.3s;
}

.toggle-slider:before {
    content: "☀️";
    position: absolute;
    height: 22px;
    width: 22px;
    left: 3px;
    bottom: 3px;
    background: white;
    border-radius: 50%;
    transition: 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}

.theme-toggle input:checked + .toggle-slider {
    background: var(--primary);
}

.theme-toggle input:checked + .toggle-slider:before {
    content: "🌙";
    transform: translateX(24px);
}

/* Main content */
.ai-main {
    flex: 1;
    padding: 48px 0 80px;
}

.ai-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Ad Slots */
.ad-slot {
    margin: 32px auto;
    text-align: center;
}

.ad-slot.ad-top {
    margin-top: 0;
    margin-bottom: 32px;
}

.ad-slot.ad-bottom {
    margin-top: 48px;
    margin-bottom: 0;
}

/* Ad Placeholder (remove when real ads are added) */
.ad-placeholder {
    min-height: 90px;
    background: var(--gray-100);
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-500);
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: var(--transition);
}

body.dark-mode .ad-placeholder {
    background: var(--gray-200);
}

.tool-title {
    margin: 0 0 12px;
    font-size: 36px;
    font-weight: 800;
    color: var(--text-color);
    letter-spacing: -0.02em;
}

.ai-lead {
    margin: 0 0 40px;
    font-size: 19px;
    color: var(--gray-600);
    line-height: 1.7;
}

body.dark-mode .ai-lead {
    color: var(--gray-400);
}

/* Homepage grid */
.ai-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.ai-card {
    padding: 32px;
    border-radius: var(--border-radius);
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.03);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

body.dark-mode .ai-card {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.ai-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), #7c3aed);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.ai-card:hover::before {
    transform: scaleX(1);
}

.ai-card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), #7c3aed);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--light);
    font-size: 24px;
    margin-bottom: 20px;
}

.ai-card h3 {
    margin: 0 0 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--text-color);
}

.ai-card p {
    margin: 0;
    font-size: 15px;
    color: var(--gray-600);
    line-height: 1.6;
}

body.dark-mode .ai-card p {
    color: var(--gray-400);
}

.ai-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: 0 12px 24px rgba(78, 82, 248, 0.15);
}

body.dark-mode .ai-card:hover {
    box-shadow: 0 12px 24px rgba(78, 82, 248, 0.3);
}

/* Forms */
.ai-form {
    margin-top: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.ai-form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.ai-label {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.ai-label-badge {
    font-size: 12px;
    font-weight: 500;
    color: var(--primary);
    background: rgba(78, 82, 248, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
}

.ai-input {
    width: 100%;
    min-height: 280px;
    font-size: 15px;
    padding: 18px;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    resize: vertical;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    background: var(--card-bg);
    transition: var(--transition);
    line-height: 1.6;
    color: var(--text-color);
}

/* Override for select dropdowns */
select.ai-input {
    min-height: auto;
    height: 50px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    resize: none;
    padding: 12px 18px;
    line-height: 1.4;
}

/* Override for text inputs */
input[type="text"].ai-input,
input[type="email"].ai-input,
input[type="password"].ai-input {
    min-height: auto;
    height: 50px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    resize: none;
    padding: 12px 18px;
    line-height: 1.4;
}

.ai-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(78, 82, 248, 0.1);
}

.ai-input::placeholder {
    color: var(--gray-400);
}

.ai-input.error {
    border-color: var(--error);
}

/* Buttons */
.ai-btn {
    background: var(--primary);
    color: var(--light);
    padding: 16px 32px;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(78, 82, 248, 0.3);
    align-self: flex-start;
}

.ai-btn:hover:not(:disabled) {
    background: var(--primary-hover);
    box-shadow: 0 6px 20px rgba(78, 82, 248, 0.4);
    transform: translateY(-2px);
}

.ai-btn:active:not(:disabled) {
    transform: translateY(0);
}

.ai-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.ai-btn.loading {
    pointer-events: none;
}

.ai-btn.loading::after {
    content: "";
    width: 18px;
    height: 18px;
    border: 2px solid var(--light);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Output */
.ai-output-wrapper {
    position: relative;
    margin-top: 32px;
}

.ai-output {
    padding: 24px;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    font-size: 15px;
    line-height: 1.8;
    white-space: pre-wrap;
    color: var(--text-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    min-height: 100px;
}

.ai-output.success {
    border-color: var(--success);
    background: var(--success-bg);
}

.ai-output.error {
    border-color: var(--error);
    background: var(--error-bg);
    color: var(--error);
}

.ai-output.thinking {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--gray-500);
}

.ai-output.thinking::before {
    content: "";
    width: 20px;
    height: 20px;
    border: 2px solid var(--primary);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

/* Copy button */
.ai-copy-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--gray-700);
    color: var(--light);
    border: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    opacity: 0.9;
    display: flex;
    align-items: center;
    gap: 6px;
}

.ai-copy-btn:hover {
    opacity: 1;
    background: var(--dark);
    transform: translateY(-1px);
}

.ai-copy-btn.copied {
    background: var(--success);
}

/* Character count */
.ai-char-count {
    font-size: 13px;
    color: var(--gray-500);
    text-align: right;
}

.ai-char-count.warning {
    color: var(--error);
    font-weight: 600;
}

/* Footer */
.ai-footer {
    margin-top: auto;
    padding: 32px 24px;
    text-align: center;
    color: var(--gray-500);
    font-size: 14px;
    border-top: 1px solid var(--border-color);
    background: var(--light);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.ai-footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-top: 16px;
}

.ai-footer-link {
    color: var(--gray-600);
    font-weight: 500;
    transition: var(--transition);
}

.ai-footer-link:hover {
    color: var(--primary);
}

/* Legal Pages */
.ai-legal-page {
    max-width: 800px;
}

.ai-meta-info {
    color: var(--gray-500);
    font-size: 14px;
    margin-bottom: 32px;
}

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

.legal-section h2 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 16px;
    margin-top: 0;
}

.legal-section h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 12px;
    margin-top: 24px;
}

.legal-section p {
    color: var(--text-color);
    line-height: 1.8;
    margin-bottom: 16px;
}

.legal-section ul,
.legal-section ol {
    color: var(--text-color);
    line-height: 1.8;
    margin-bottom: 16px;
    padding-left: 24px;
}

.legal-section li {
    margin-bottom: 8px;
}

.legal-section a {
    color: var(--primary);
    text-decoration: underline;
}

.legal-section a:hover {
    color: var(--primary-hover);
}

/* About Page Tools Grid */
.about-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-top: 32px;
}

.about-tool-card {
    background: var(--card-bg);
    padding: 24px;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    text-align: center;
}

.about-tool-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.about-tool-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 12px;
}

.about-tool-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.6;
    margin: 0;
}

body.dark-mode .about-tool-card p {
    color: var(--gray-400);
}

/* Contact Page */
.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-top: 32px;
}

.contact-card {
    background: var(--card-bg);
    padding: 24px;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    text-align: center;
}

.contact-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.contact-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 12px;
}

.contact-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.6;
    margin: 8px 0;
}

.contact-card strong {
    color: var(--primary);
    font-weight: 600;
}

body.dark-mode .contact-card p {
    color: var(--gray-400);
}

.faq-item {
    margin-bottom: 32px;
}

.faq-item h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 8px;
}

.faq-item p {
    color: var(--text-color);
    line-height: 1.7;
}

.social-links p {
    margin: 12px 0;
    font-size: 15px;
}

/* Responsive */
@media (max-width: 768px) {
    .ai-container {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    .ai-header-right {
        width: 100%;
        justify-content: space-between;
    }

    .ai-global-nav {
        flex: 1;
    }

    .tool-title {
        font-size: 28px;
    }

    .ai-lead {
        font-size: 17px;
    }

    .ai-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .ai-input {
        min-height: 220px;
    }

    .ai-btn {
        width: 100%;
    }
}

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

    .tool-title {
        font-size: 24px;
    }

    .ai-card {
        padding: 24px;
    }

    .ai-copy-btn {
        position: static;
        margin-top: 16px;
        width: 100%;
    }
}