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

:root {
    --bg: #f5f5f7;
    --bg-card: #ffffff;
    --text: #1d1d1f;
    --text-secondary: #6e6e73;
    --accent: #0071e3;
    --accent-hover: #0077ed;
    --border: #d2d2d7;
    --overlay: rgba(0,0,0,0.45);
    --danger: #ff3b30;
    --success: #34c759;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --radius: 16px;
    --transition: 0.3s ease;
}

[data-theme="dark"] {
    --bg: #1d1d1f;
    --bg-card: #2c2c2e;
    --text: #f5f5f7;
    --text-secondary: #98989d;
    --accent: #0a84ff;
    --accent-hover: #409cff;
    --border: #48484a;
    --overlay: rgba(0,0,0,0.65);
    --shadow: 0 2px 12px rgba(0,0,0,0.3);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    transition: background var(--transition), color var(--transition);
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background var(--transition), border-color var(--transition);
}

.header h1 {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.theme-toggle {
    background: none;
    border: 2px solid var(--border);
    border-radius: 50%;
    width: 42px;
    height: 42px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    transition: border-color var(--transition), transform 0.2s;
    color: var(--text);
}

.theme-toggle:hover {
    border-color: var(--accent);
    transform: scale(1.1);
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 32px 20px 60px;
}

.section-title {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text);
}

.upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: border-color var(--transition), background var(--transition);
    background: var(--bg-card);
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--accent);
    background: rgba(0,113,227,0.04);
}

.upload-zone .icon {
    font-size: 40px;
    margin-bottom: 8px;
}

.upload-zone p {
    color: var(--text-secondary);
    font-size: 15px;
}

.upload-zone .hint {
    font-size: 13px;
    margin-top: 6px;
    color: var(--text-secondary);
    opacity: 0.7;
}

#fileInput {
    display: none;
}

.photos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px;
    margin-top: 16px;
}

.photo-card {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    aspect-ratio: 1;
    background: var(--bg-card);
    border: 1px solid var(--border);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.photo-card:hover {
    box-shadow: var(--shadow);
}

.photo-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    cursor: zoom-in;
}

.photo-card .remove-btn {
    position: absolute;
    top: 6px;
    right: 6px;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--overlay);
    border: none;
    color: #fff;
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.2s;
}

.photo-card:hover .remove-btn {
    opacity: 1;
}

.combo-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 16px;
    margin-top: 24px;
    font-size: 17px;
    font-weight: 600;
    color: #fff;
    background: var(--accent);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: background var(--transition), transform 0.15s;
}

.combo-btn:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

.combo-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
}

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

.result-section {
    margin-top: 32px;
    display: none;
}

.result-section.visible {
    display: block;
}

.result-image-wrapper {
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--bg-card);
    border: 1px solid var(--border);
    transition: border-color var(--transition);
}

.result-image-wrapper img {
    width: 100%;
    display: block;
    cursor: zoom-in;
}

.result-actions {
    display: flex;
    gap: 10px;
    margin-top: 14px;
}

.action-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 12px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text);
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition), transform 0.15s;
}

.action-btn:hover {
    border-color: var(--accent);
    transform: translateY(-1px);
}

.action-btn .btn-icon {
    font-size: 18px;
}

.error-toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--danger);
    color: #fff;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    opacity: 0;
    transition: transform 0.3s, opacity 0.3s;
    z-index: 200;
    max-width: 90vw;
    text-align: center;
}

.error-toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--overlay);
    z-index: 150;
    align-items: center;
    justify-content: center;
    cursor: zoom-out;
}

.lightbox.open {
    display: flex;
}

.lightbox img {
    max-width: 92vw;
    max-height: 92vh;
    border-radius: 8px;
    object-fit: contain;
}

.counter {
    display: inline-block;
    font-size: 13px;
    color: var(--text-secondary);
    margin-left: 6px;
    font-weight: 400;
}

@media (max-width: 480px) {
    .header {
        padding: 12px 16px;
    }

    .header h1 {
        font-size: 19px;
    }

    .theme-toggle {
        width: 38px;
        height: 38px;
        font-size: 18px;
    }

    .container {
        padding: 20px 12px 48px;
    }

    .upload-zone {
        padding: 28px 16px;
    }

    .upload-zone .icon {
        font-size: 32px;
    }

    .upload-zone p {
        font-size: 14px;
    }

    .photos-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .photo-card .remove-btn {
        opacity: 1;
        width: 26px;
        height: 26px;
        font-size: 14px;
    }

    .combo-btn {
        padding: 14px;
        font-size: 16px;
    }

    .action-btn {
        padding: 10px;
        font-size: 14px;
    }

    .section-title {
        font-size: 15px;
    }
}

@media (min-width: 481px) and (max-width: 768px) {
    .container {
        padding: 28px 16px 52px;
    }

    .photos-grid {
        grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    }
}