/* CSS Variables for Theme Management */
:root {
    /* Light Theme Colors */
    --primary-color: #1976d2;
    --primary-dark: #1565c0;
    --primary-light: #42a5f5;
    --secondary-color: #dc004e;
    --accent-color: #00bcd4;
    
    --background-color: #ffffff;
    --surface-color: #f5f5f5;
    --card-color: #ffffff;
    --text-primary: #212121;
    --text-secondary: #757575;
    --text-disabled: #bdbdbd;
    --divider-color: #e0e0e0;
    
    --success-color: #4caf50;
    --warning-color: #ff9800;
    --error-color: #f44336;
    --info-color: #2196f3;
    
    --shadow-1: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-2: 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
    --shadow-3: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
    --shadow-4: 0 14px 28px rgba(0,0,0,0.25), 0 10px 10px rgba(0,0,0,0.22);
    
    --border-radius: 8px;
    --border-radius-large: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme */
[data-theme="dark"] {
    --background-color: #121212;
    --surface-color: #1e1e1e;
    --card-color: #2d2d2d;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --text-disabled: #666666;
    --divider-color: #404040;
    
    --shadow-1: 0 1px 3px rgba(0,0,0,0.5), 0 1px 2px rgba(0,0,0,0.6);
    --shadow-2: 0 3px 6px rgba(0,0,0,0.6), 0 3px 6px rgba(0,0,0,0.7);
    --shadow-3: 0 10px 20px rgba(0,0,0,0.7), 0 6px 6px rgba(0,0,0,0.8);
    --shadow-4: 0 14px 28px rgba(0,0,0,0.8), 0 10px 10px rgba(0,0,0,0.9);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-color);
    transition: var(--transition);
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 500;
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--background-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.3s ease;
}

.loading-screen.hidden {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--divider-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Header */
.header {
    background: var(--card-color);
    box-shadow: var(--shadow-1);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: var(--transition);
    border-bottom: 1px solid var(--divider-color);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 500;
    margin: 0;
}

.nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Top Navbar Links */
.top-nav-links {
    display: flex;
    gap: 12px;
    align-items: center;
    margin-left: auto;
}

.top-nav-links .nav-link {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 0.75rem;
    text-decoration: none;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    font-weight: 500;
}

.top-nav-links .nav-link:hover {
    color: var(--primary-color);
}

.top-nav-links .nav-link::after {
    content: '';
    position: absolute;
    left: 12px;
    right: 12px;
    bottom: -8px;
    height: 2px;
    background: transparent;
    transition: var(--transition-fast);
    border-radius: 2px;
}

.top-nav-links .nav-link:hover::after {
    background: var(--divider-color);
}

.top-nav-links .nav-link[aria-current="page"],
.top-nav-links .nav-link.active {
    color: var(--primary-dark);
}

.top-nav-links .nav-link[aria-current="page"]::after,
.top-nav-links .nav-link.active::after {
    background: var(--primary-color);
}

.theme-toggle,
.help-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover,
.help-btn:hover {
    background: var(--surface-color);
    color: var(--primary-color);
}

/* Main Content */
.main {
    min-height: calc(100vh - 80px);
    padding: 2rem 0;
}

/* Feedback Page */
.feedback-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

/* Keep single-column layout even on wide screens when no aside/image is present */
@media (min-width: 900px) {
    .feedback-section {
        grid-template-columns: 1fr;
        align-items: start;
    }
}

.feedback-card {
    background: var(--card-color);
    border: 1px solid var(--divider-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-1);
    padding: 20px;
}

/* Colorful accents for feedback form */
.feedback-card h2 {
    display: flex;
    align-items: center;
    gap: 12px;
}

.feedback-badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.8rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: #fff;
    box-shadow: var(--shadow-2);
}

.feedback-form .tool-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.feedback-form .tool-btn:hover {
    filter: brightness(1.05);
}

/* Small image near title */
.feedback-title-wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.feedback-title-image {
    width: 64px;
    height: 64px;
    object-fit: contain;
    border-radius: 12px;
    box-shadow: var(--shadow-1);
    border: 1px solid var(--divider-color);
}

.feedback-form .form-field {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 12px;
}

.feedback-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

@media (min-width: 720px) {
    .feedback-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.feedback-form label {
    color: var(--text-primary);
    font-weight: 500;
}

.feedback-form input,
.feedback-form textarea {
    padding: 0.75rem 0.9rem;
    border: 2px solid var(--divider-color);
    border-radius: var(--border-radius);
    background: var(--card-color);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition-fast);
}

.feedback-form input:focus,
.feedback-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.08);
}

.form-actions {
    margin-top: 12px;
}

.feedback-image {
    width: 100%;
    max-width: 420px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-2);
    border: 1px solid var(--divider-color);
    background: var(--card-color);
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
}

.hero h2 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 400;
}

.hero p {
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Search Section */
.search-section {
    margin-bottom: 2rem;
}

.search-container {
    position: relative;
    max-width: 500px;
    margin: 0 auto 2rem;
}

.search-container i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

#tool-search {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 2px solid var(--divider-color);
    border-radius: var(--border-radius);
    background: var(--card-color);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition-fast);
}

#tool-search:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(25, 118, 210, 0.1);
}

/* Filter Tabs */
.filter-tabs {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-tab {
    background: none;
    border: 2px solid var(--divider-color);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition-fast);
    font-weight: 500;
}

.filter-tab:hover {
    border-color: var(--primary-light);
    color: var(--primary-color);
}

.filter-tab.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* Tools Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.tool-card {
    background: var(--card-color);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-1);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-3);
    border-color: var(--primary-light);
}

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

.tool-card.hidden {
    display: none;
}

.tool-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.tool-card:hover .tool-icon {
    transform: scale(1.1);
}

.tool-icon i {
    color: white;
    font-size: 2rem;
}

.tool-card h3 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.tool-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition-fast);
    width: 100%;
    justify-content: center;
}

.tool-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .header-content {
        padding: 0.75rem 0;
    }
    
    .logo h1 {
        font-size: 1.25rem;
    }
    
    .hero {
        padding: 1rem 0;
        margin-bottom: 2rem;
    }
    
    .hero h2 {
        font-size: 1.75rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .tool-card {
        padding: 1.5rem;
    }
    
    .filter-tabs {
        gap: 0.25rem;
    }
    
    .filter-tab {
        padding: 0.5rem 0.75rem;
        font-size: 0.875rem;
    }
}

@media (max-width: 480px) {
    .search-container {
        margin-bottom: 1rem;
    }
    
    #tool-search {
        padding: 0.75rem 0.75rem 0.75rem 2.5rem;
    }
    
    .tool-card {
        padding: 1rem;
    }
    
    .tool-icon {
        width: 48px;
        height: 48px;
        margin-bottom: 1rem;
    }
    
    .tool-icon i {
        font-size: 1.5rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles */
button:focus,
input:focus,
.tool-card:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --shadow-1: 0 2px 4px rgba(0,0,0,0.8);
        --shadow-2: 0 4px 8px rgba(0,0,0,0.8);
        --shadow-3: 0 8px 16px rgba(0,0,0,0.8);
    }
    
    .tool-card {
        border: 2px solid var(--divider-color);
    }
}

/* Print Styles */
@media print {
    .header,
    .search-section,
    .modal,
    .notification-container {
        display: none !important;
    }
    
    .tools-grid {
        display: block;
    }
    
    .tool-card {
        break-inside: avoid;
        margin-bottom: 1rem;
        box-shadow: none;
        border: 1px solid #ccc;
    }
}