/**
 * COLLAGE.CSS - Photo Collage Maker
 * Light Theme - Professional & Premium
 */

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

:root {
    --bg: #ffffff;
    --bg-light: #f8f9fa;
    --bg-card: #ffffff;
    --text: #1a1a1a;
    --text-secondary: #555555;
    --text-muted: #888888;
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: rgba(236, 72, 153, 0.1);
    --success: #22c55e;
    --border: #e5e5e5;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --radius: 10px;
    --radius-lg: 14px;
    --shadow: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

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

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.back-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: #f5f5f5;
    border-radius: 10px;
    color: #333;
    margin-right: 12px;
    transition: all 0.2s;
    text-decoration: none;
}

.back-btn:hover {
    background: var(--primary);
    color: white;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
    font-weight: 700;
    font-size: 1.2rem;
}

.logo__icon {
    width: 32px;
    height: 32px;
    color: var(--primary);
}

.nav {
    display: flex;
    gap: 24px;
}

.nav__link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.nav__link:hover,
.nav__link--active {
    color: var(--primary);
}

/* Pages */
.page {
    display: none;
    min-height: calc(100vh - 150px);
}

.page.active {
    display: flex;
    flex-direction: column;
}

#page-upload {
    justify-content: center;
    align-items: center;
    padding: 40px 0;
}

/* Upload Box */
.upload-box {
    text-align: center;
    padding: 60px 20px;
    max-width: 600px;
    margin: 0 auto;
}

.upload-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text);
}

.upload-desc {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 40px;
}

.upload-desc .highlight {
    color: var(--primary);
}

/* Dropzone */
.dropzone {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.upload-btn {
    display: inline-flex;
    padding: 18px 48px;
    font-size: 18px;
    font-weight: 600;
    color: white;
    background: var(--primary);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow);
    border: none;
}

.upload-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}

.upload-hint {
    margin-top: 16px;
    font-size: 14px;
    color: var(--text-muted);
}

/* Upload Area - for JS compatibility */
.upload-area {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.upload-area.dragover .upload-btn {
    background: var(--primary-hover);
    transform: scale(1.05);
}

.upload-content {
    text-align: center;
    padding: 40px;
}

.upload-content svg {
    width: 80px;
    height: 80px;
    color: var(--primary);
    margin-bottom: 24px;
}

.upload-content h2 {
    font-size: 1.5rem;
    margin-bottom: 8px;
    color: var(--text);
}

.upload-content p {
    color: var(--text-muted);
    margin-bottom: 24px;
}

.btn-select {
    padding: 14px 32px;
    background: var(--primary);
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 14px rgba(236, 72, 153, 0.3);
}

.btn-select:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(236, 72, 153, 0.4);
}

/* Features Grid */
.features-grid {
    display: flex;
    gap: 40px;
    margin-top: 60px;
    flex-wrap: wrap;
    justify-content: center;
}

.feature {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-secondary);
}

.feature svg {
    width: 24px;
    height: 24px;
    color: var(--primary);
}

/* Editor Layout */
.editor-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: calc(100vh - 80px);
}

/* Controls */
.controls {
    background: var(--bg);
    padding: 24px;
    border-right: 1px solid var(--border);
    overflow-y: auto;
}

.controls h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    margin-bottom: 16px;
    margin-top: 24px;
}

.controls h3:first-child {
    margin-top: 0;
}

/* Layout Grid */
.layout-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.layout-btn {
    aspect-ratio: 1;
    padding: 8px;
    background: var(--bg-light);
    border: 2px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.layout-btn:hover {
    border-color: var(--primary);
}

.layout-btn.active {
    border-color: var(--primary);
    background: var(--primary-light);
}

.layout-btn svg {
    width: 100%;
    height: 100%;
    color: var(--text-muted);
}

.layout-btn.active svg {
    color: var(--primary);
}

/* Color Options */
.color-options {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.color-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.2s;
}

.color-btn:hover {
    transform: scale(1.1);
}

.color-btn.active {
    border-color: var(--primary);
    box-shadow: 0 0 0 2px var(--primary);
}

#custom-color {
    width: 36px;
    height: 36px;
    padding: 0;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

/* Slider Group */
.slider-group {
    margin-bottom: 16px;
}

.slider-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text);
    margin-bottom: 8px;
}

.slider-group input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-light);
    border: 1px solid var(--border);
    appearance: none;
    cursor: pointer;
}

.slider-group input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(236, 72, 153, 0.3);
}

/* Size Options */
.size-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.size-btn {
    padding: 12px 16px;
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 0.85rem;
    text-align: left;
    cursor: pointer;
    transition: all 0.2s;
}

.size-btn:hover {
    border-color: var(--primary);
}

.size-btn.active {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}

/* Create Button */
.btn-create {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px;
    margin-top: 32px;
    background: var(--primary);
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 14px rgba(236, 72, 153, 0.3);
}

.btn-create:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(236, 72, 153, 0.4);
}

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

/* Preview Section */
.preview-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    background: var(--bg-light);
}

.preview-wrapper {
    max-width: 100%;
    max-height: calc(100vh - 200px);
}

.preview-container {
    background: white;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius);
}

.hint {
    margin-top: 20px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Collage Preview */
.collage-grid {
    display: grid;
    gap: 10px;
    padding: 20px;
}

.collage-cell {
    background: var(--bg-light);
    border-radius: 0;
    overflow: hidden;
    position: relative;
    cursor: move;
    border: 1px solid var(--border);
}

.collage-cell img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.collage-cell.empty {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* Download Page */
#page-download {
    justify-content: center;
    align-items: center;
    padding: 40px 0;
}

.download-card {
    background: var(--bg);
    border-radius: 20px;
    padding: 48px;
    text-align: center;
    max-width: 500px;
    width: 100%;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
}

.success-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: rgba(34, 197, 94, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.success-icon svg {
    width: 40px;
    height: 40px;
    color: var(--success);
}

.download-card h2 {
    font-size: 1.8rem;
    margin-bottom: 8px;
    color: var(--text);
}

.download-card > p {
    color: var(--text-muted);
    margin-bottom: 24px;
}

.result-preview {
    margin-bottom: 24px;
}

.result-preview img {
    max-width: 100%;
    max-height: 300px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.download-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
}

.btn-download {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 24px;
    background: var(--primary);
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 14px rgba(236, 72, 153, 0.3);
}

.btn-download:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(236, 72, 153, 0.4);
}

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

.btn-new {
    padding: 14px 24px;
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-new:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Share Section */
.share-section {
    margin-bottom: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.share-section p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.share-btns {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.share-btn {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s;
}

.share-btn:hover {
    transform: scale(1.1);
}

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

.share-btn.twitter { background: #1DA1F2; color: white; }
.share-btn.whatsapp { background: #25D366; color: white; }
.share-btn.copy { background: var(--bg-light); color: var(--text); border: 1px solid var(--border); }

/* Privacy Note */
.privacy-note {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--success);
}

.privacy-note svg {
    width: 16px;
    height: 16px;
}

/* Footer */
.footer {
    background: var(--bg);
    border-top: 1px solid var(--border);
    padding: 24px;
    text-align: center;
}

.footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Mobile Responsive */
@media (max-width: 900px) {
    .editor-layout {
        grid-template-columns: 1fr;
    }
    
    .controls {
        border-right: none;
        border-bottom: 1px solid var(--border);
        max-height: 50vh;
        overflow-y: auto;
    }
    
    .layout-grid {
        grid-template-columns: repeat(6, 1fr);
    }
    
    .size-options {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .size-btn {
        flex: 1;
        min-width: 120px;
        text-align: center;
    }
}

@media (max-width: 600px) {
    .header__inner {
        flex-direction: column;
        gap: 16px;
    }
    
    .nav {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
        gap: 16px;
    }
    
    .features-grid {
        flex-direction: column;
        gap: 20px;
    }
    
    .download-card {
        padding: 32px 20px;
    }
}