/* CSS Variables - Light Mode (Default) */
:root {
    /* Brand Colors - Using blue-600 like phuyu-translator */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #3b82f6;

    /* Text Colors - Zinc palette */
    --text-primary: #18181b;
    --text-secondary: #71717a;
    --text-muted: #a1a1aa;

    /* Icon Colors - Dark icon on light background */
    --icon-color: #52525b;

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #fafafa;
    --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);

    /* Card Colors */
    --card-bg: rgba(255, 255, 255, 0.7);
    --card-border: rgba(255, 255, 255, 0.5);

    /* Navigation */
    --nav-bg: rgba(255, 255, 255, 0.8);
    --nav-border: rgba(244, 244, 245, 1);

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

    /* Border Colors */
    --border-color: #e4e4e7;
    --border-hover: #d4d4d8;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode */
.dark {
    --text-primary: #f4f4f5;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;

    /* Icon Colors - Light icon on dark background */
    --icon-color: #d4d4d8;

    --bg-primary: #09090b;
    --bg-secondary: #18181b;
    --bg-gradient: linear-gradient(135deg, #0a0a0b 0%, #0f0f11 100%);

    --card-bg: rgba(24, 24, 27, 0.7);
    --card-border: rgba(39, 39, 42, 1);

    --nav-bg: rgba(9, 9, 11, 0.8);
    --nav-border: rgba(39, 39, 42, 1);

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.5);

    --border-color: #27272a;
    --border-hover: #3f3f46;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-normal), color var(--transition-normal);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Navigation */
header {
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--nav-border);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

/* Header controls container for lang-switcher and theme-toggle */
.header-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.8;
}

.logo-icon {
    height: 2rem;
    width: auto;
    transition: transform var(--transition-smooth);
}

.logo-icon.light {
    display: block;
}

.logo-icon.dark {
    display: none;
}

.dark .logo-icon.light {
    display: none;
}

.dark .logo-icon.dark {
    display: block;
}

.logo:hover .logo-icon {
    transform: scale(1.05);
}

.logo-text {
    letter-spacing: -0.025em;
}

/* Language Switcher */
.lang-switcher {
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    outline: none;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    padding-right: 2.5rem;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2371717a' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1rem;
}

.dark .lang-switcher {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23a1a1aa' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
}

.lang-switcher:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.lang-switcher:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 4rem 2rem;
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hero Card */
.hero-card {
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 1.5rem;
    box-shadow: var(--shadow-xl);
    max-width: 600px;
    width: 100%;
    border: 1px solid var(--card-border);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.hero-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

.dark .hero-card:hover {
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

/* Typography */
h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
    letter-spacing: -0.025em;
    line-height: 1.2;
}

p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 2rem;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}

/* Primary CTA Button */
.cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 2rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 1rem;
    border: 2px solid var(--primary-color);
    transition: all var(--transition-smooth);
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.cta-button:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

.cta-button:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(37, 99, 235, 0.3);
}

/* Secondary CTA Button */
.cta-button.secondary {
    background: transparent;
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
    border: 2px solid var(--primary-color);
}

.cta-button.secondary:hover {
    background: rgba(37, 99, 235, 0.05);
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.15);
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Redirect Page Styles */
.redirect-body {
    justify-content: center;
    align-items: center;
}

.redirect-container {
    text-align: center;
    animation: fadeIn 0.8s ease-out;
}

.redirect-container h1.logo {
    justify-content: center;
    margin-bottom: 2rem;
}

.redirect-container p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.manual-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.manual-links a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    transition: all var(--transition-fast);
}

.manual-links a:hover {
    background: rgba(37, 99, 235, 0.05);
    text-decoration: none;
    transform: translateY(-1px);
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        padding: 1rem 1.5rem;
    }

    .logo {
        font-size: 1.25rem;
    }

    .logo-icon {
        height: 1.5rem;
    }

    .lang-switcher {
        padding: 0.5rem 0.75rem;
        font-size: 0.8125rem;
        padding-right: 2rem;
    }

    main {
        padding: 2rem 1.5rem;
    }

    .hero-card {
        padding: 2rem;
    }

    h1 {
        font-size: 2rem;
    }

    p {
        font-size: 1rem;
    }

    .cta-button {
        padding: 0.75rem 1.75rem;
        font-size: 0.9375rem;
    }

    .manual-links {
        flex-direction: column;
        gap: 0.75rem;
    }

    .manual-links a {
        display: inline-block;
        padding: 0.75rem 1.5rem;
        border: 1px solid var(--border-color);
        border-radius: 0.5rem;
    }

    .manual-links a:hover {
        border-color: var(--primary-color);
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }

    .hero-card {
        padding: 1.5rem;
    }

    .action-buttons {
        flex-direction: column;
    }

    .cta-button {
        width: 100%;
    }
}

/* Focus Styles for Accessibility */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Smooth scroll behavior for anchor links */
a {
    color: inherit;
}

/* Selection styling */
::selection {
    background: rgba(37, 99, 235, 0.2);
    color: var(--text-primary);
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Theme Toggle Button */
.theme-toggle {
    padding: 0.5rem;
    border-radius: 9999px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--icon-color);
    cursor: pointer;
    outline: none;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
}

.theme-toggle:hover {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
}

.theme-toggle:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.theme-toggle .sun-icon {
    display: block;
}

.theme-toggle .moon-icon {
    display: none;
}

.dark .theme-toggle .sun-icon {
    display: none;
}

.dark .theme-toggle .moon-icon {
    display: block;
}