/* ==================== CSS Variables ==================== */
:root {
    /* Colors - Dark Theme */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-card: #15151f;
    --bg-card-hover: #1c1c2a;

    /* Accent Colors */
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --accent-glow: 0 0 20px rgba(99, 102, 241, 0.3);

    /* Tier Colors */
    --tier-free: #6b7280;
    --tier-1: #3b82f6;
    --tier-2: #f59e0b;
    --tier-2-gradient: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);

    /* Boost Color */
    --boost-color: #10b981;
    --boost-glow: 0 0 15px rgba(16, 185, 129, 0.4);

    /* Text Colors */
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    /* Border Colors */
    --border-color: #2a2a3a;
    --border-light: #3a3a4a;

    /* Status Colors */
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.6);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
}

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

html {
    scroll-behavior: smooth;
}

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

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

a:hover {
    color: var(--accent-secondary);
}

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

button {
    cursor: pointer;
    font-family: inherit;
    font-size: inherit;
    border: none;
    background: none;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* ==================== Layout ==================== */
.container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-2xl) 0;
}

/* ==================== Navigation ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
}

.navbar-brand svg {
    width: 32px;
    height: 32px;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    list-style: none;
}

.navbar-nav a {
    color: var(--text-secondary);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.navbar-nav a:hover,
.navbar-nav a.active {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* ==================== Buttons ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-light);
}

.btn-boost {
    background: var(--boost-color);
    color: white;
    box-shadow: var(--boost-glow);
}

.btn-boost:hover {
    background: #0d9668;
    transform: translateY(-2px);
}

.btn-tier2 {
    background: var(--tier-2-gradient);
    color: white;
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* ==================== Forms ==================== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--text-secondary);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

/* ==================== Cards ==================== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
}

.card:hover {
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* ==================== Badges ==================== */
.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
}

.badge-category {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.badge-tier1 {
    background: rgba(59, 130, 246, 0.2);
    color: var(--tier-1);
    border: 1px solid var(--tier-1);
}

.badge-tier2 {
    background: rgba(245, 158, 11, 0.2);
    color: var(--tier-2);
    border: 1px solid var(--tier-2);
}

.badge-boost {
    background: rgba(16, 185, 129, 0.2);
    color: var(--boost-color);
}

/* ==================== Modal ==================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.modal-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

.modal-close {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

/* ==================== Toast Notifications ==================== */
.toast-container {
    position: fixed;
    top: 80px;
    right: var(--spacing-lg);
    z-index: 3000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    color: white;
    font-weight: 500;
    animation: slideIn 0.3s ease, fadeOut 0.3s ease 2.7s forwards;
    min-width: 250px;
}

.toast-success {
    background: var(--success);
}

.toast-error {
    background: var(--error);
}

.toast-warning {
    background: var(--warning);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

/* ==================== Loading ==================== */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ==================== User Menu ==================== */
.user-menu {
    position: relative;
    display: flex;
    align-items: center;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid var(--border-color);
    transition: border-color var(--transition-fast);
    background: var(--accent-gradient);
    color: white;
    font-weight: 600;
    font-size: var(--font-size-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.user-avatar:hover {
    border-color: var(--accent-primary);
}

.user-dropdown {
    position: absolute;
    top: calc(100% + var(--spacing-sm));
    right: 0;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-lg);
    z-index: 100;
}

.user-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-dropdown hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 0;
}

.user-info {
    padding: var(--spacing-md);
}

.user-name {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
}

.user-email {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-md);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    text-align: left;
}

.dropdown-item:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.dropdown-item svg {
    width: 16px;
    height: 16px;
}

/* ==================== Google Sign-In Button ==================== */
.google-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: white;
    color: #333;
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.google-btn:hover {
    background: #f5f5f5;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.google-btn svg {
    width: 20px;
    height: 20px;
}

/* ==================== Responsive ==================== */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .navbar-nav {
        display: none;
    }

    .modal {
        margin: var(--spacing-md);
        max-height: calc(100vh - var(--spacing-xl));
    }
}

/* ==================== Utility Classes ==================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success); }
.text-error { color: var(--error); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }