/* ============================================
   ImageTools.club — Premium Design System
   ============================================ */

/* --- CSS Variables --- */
:root {
    --primary: #3B82F6;
    --primary-hover: #2563EB;
    --accent: #8B5CF6;
    --accent-hover: #7C3AED;
    --success: #10B981;
    --warning: #F59E0B;
    --error: #EF4444;

    --bg: #FAFBFE;
    --bg-secondary: #F1F5F9;
    --card: #FFFFFF;
    --card-hover: #F8FAFC;
    --border: #E2E8F0;
    --text: #1E293B;
    --text-secondary: #64748B;
    --text-muted: #94A3B8;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans', Helvetica, Arial, sans-serif;
    --mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, monospace;

    --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);

    --header-height: 64px;
    --max-width: 1200px;
}

[data-theme="dark"] {
    --bg: #0F1117;
    --bg-secondary: #161922;
    --card: #1A1D2E;
    --card-hover: #222640;
    --border: #2D3348;
    --text: #F1F5F9;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.3);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.4);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.5);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    transition: background var(--transition), color var(--transition);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

button {
    cursor: pointer;
    font-family: var(--font);
    border: none;
    outline: none;
}

input, select, textarea {
    font-family: var(--font);
    border: none;
    outline: none;
}

/* --- Header --- */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--header-height);
    background: rgba(250, 251, 254, 0.85);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition), border var(--transition);
}

[data-theme="dark"] .header {
    background: rgba(15, 17, 23, 0.85);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    white-space: nowrap;
}

.logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.1rem;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 4px;
}

.header-nav > a,
.nav-dropdown > .nav-trigger {
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition);
    text-decoration: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    background: none;
}

.header-nav > a:hover,
.nav-dropdown:hover > .nav-trigger {
    color: var(--text);
    background: var(--bg-secondary);
}

/* Dropdown */
.nav-dropdown {
    position: relative;
}

.nav-trigger::after {
    content: '▾';
    font-size: 0.7rem;
    opacity: 0.6;
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(8px);
    min-width: 220px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s ease;
    z-index: 1001;
}

.nav-dropdown:hover .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.nav-dropdown-menu a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 0.88rem;
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition);
}

.nav-dropdown-menu a:hover {
    background: var(--bg-secondary);
    color: var(--primary);
}

.nav-dropdown-menu a .nav-icon {
    font-size: 1rem;
    width: 24px;
    text-align: center;
}

.nav-dropdown-menu a .nav-desc {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 400;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--text-secondary);
    transition: all var(--transition);
    margin-left: 8px;
}

.theme-toggle:hover {
    background: var(--card);
    color: var(--text);
    transform: rotate(15deg);
    box-shadow: var(--shadow-md);
}

/* Mobile menu */
.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text);
    font-size: 1.4rem;
    align-items: center;
    justify-content: center;
}

/* --- Hero Section --- */
.hero {
    text-align: center;
    padding: 40px 24px 30px;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 32px;
    line-height: 1.7;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
    animation: fadeInDown 0.6s ease;
}

.hero-badge .dot {
    width: 8px;
    height: 8px;
    background: var(--success);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(1.2); }
}

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

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Tool Grid --- */
.tools-section {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px 80px;
}

.tools-section h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.tools-section .section-subtitle {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.tool-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    text-decoration: none;
    color: var(--text);
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    gap: 12px;
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity var(--transition);
}

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

.tool-card:hover::before {
    opacity: 1;
}

.tool-card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    background: linear-gradient(135deg, rgba(59,130,246,0.1), rgba(139,92,246,0.1));
}

[data-theme="dark"] .tool-card-icon {
    background: linear-gradient(135deg, rgba(59,130,246,0.15), rgba(139,92,246,0.15));
}

.tool-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

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

.tool-card-arrow {
    position: absolute;
    top: 28px;
    right: 28px;
    font-size: 1.1rem;
    color: var(--text-muted);
    transition: all var(--transition);
}

.tool-card:hover .tool-card-arrow {
    color: var(--primary);
    transform: translateX(4px);
}

/* --- Upload Area --- */
.upload-area {
    max-width: 700px;
    margin: 0 auto 40px;
    padding: 60px 40px;
    border: 2px dashed var(--border);
    border-radius: var(--radius-xl);
    background: var(--card);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.upload-area::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(59,130,246,0.03), rgba(139,92,246,0.03));
    opacity: 0;
    transition: opacity var(--transition);
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: var(--primary);
    background: var(--card-hover);
    transform: scale(1.01);
    box-shadow: var(--shadow-md);
}

.upload-area:hover::before,
.upload-area.drag-over::before {
    opacity: 1;
}

.upload-area .upload-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    display: block;
    color: var(--primary);
    opacity: 0.8;
}

.upload-area h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.upload-area p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.upload-area input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

/* --- Editor Layout --- */
.editor-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px 60px;
}

.editor-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 24px;
    align-items: start;
}

.preview-pane {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.preview-pane canvas,
.preview-pane img {
    max-width: 100%;
    max-height: 500px;
    border-radius: var(--radius-sm);
}

.controls-pane {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.control-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.control-group input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-secondary);
    appearance: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(59,130,246,0.3);
}

.control-group input[type="number"],
.control-group input[type="text"],
.control-group select {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-size: 0.9rem;
    transition: all var(--transition);
}

.control-group input:focus,
.control-group select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.1);
}

.info-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
}

.info-row .label {
    color: var(--text-secondary);
}

.info-row .value {
    font-weight: 600;
    color: var(--text);
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    box-shadow: 0 4px 15px rgba(59,130,246,0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(59,130,246,0.4);
}

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

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

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

.btn-download {
    width: 100%;
    padding: 14px 24px;
    background: linear-gradient(135deg, var(--success), #059669);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    box-shadow: 0 4px 15px rgba(16,185,129,0.3);
    transition: all var(--transition);
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(16,185,129,0.4);
}

.btn-download:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* --- Features Section --- */
.features {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 60px 24px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 32px;
}

.feature-item {
    text-align: center;
    padding: 32px 24px;
}

.feature-item .icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
    display: block;
}

.feature-item h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --- SEO Content --- */
.seo-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px;
    text-align: center;
}

.seo-content h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.seo-content p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 16px;
}

/* --- Footer --- */
.footer {
    border-top: 1px solid var(--border);
    background: var(--card);
    padding: 48px 24px;
    transition: background var(--transition), border var(--transition);
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-top: 12px;
}

.footer-col h4 {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.footer-col a {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    padding: 4px 0;
    transition: color var(--transition);
}

.footer-col a:hover {
    color: var(--primary);
}

.footer-bottom {
    max-width: var(--max-width);
    margin: 32px auto 0;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* --- Utility Classes --- */
.hidden { display: none !important; }
.text-center { text-align: center; }
.mt-2 { margin-top: 16px; }
.mt-4 { margin-top: 32px; }
.mb-2 { margin-bottom: 16px; }

/* --- Loading Spinner --- */
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* --- Toast Notifications --- */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    padding: 14px 24px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    font-size: 0.9rem;
    color: var(--text);
    z-index: 9999;
    animation: slideUp 0.3s ease;
}

.toast.success { border-left: 4px solid var(--success); }
.toast.error { border-left: 4px solid var(--error); }

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .hero { padding: 50px 20px 40px; }
    .hero h1 { font-size: 2rem; }

    .tool-grid {
        grid-template-columns: 1fr;
    }

    .editor-layout {
        grid-template-columns: 1fr;
    }

    .footer-inner {
        grid-template-columns: 1fr 1fr;
        gap: 24px;
    }

    .header-nav {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    .upload-area {
        padding: 40px 24px;
    }

    .features {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .footer-inner {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }
}