/* ===== Reset + Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    min-height: 100vh;
    transition: background var(--transition-fast), color var(--transition-fast);
}

/* ===== CSS Variables ===== */
:root {
    --color-primary: #667eea;
    --color-secondary: #764ba2;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    --bg-body: #f5f5f5;
    --bg-page: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-container: rgba(255, 255, 255, 0.95);
    --bg-card: #fafafa;

    --text-primary: #333;
    --text-secondary: #555;
    --text-muted: #666;

    --border-color: #e0e0e0;
    --shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 15px 35px rgba(0, 0, 0, 0.15);

    --accent: #3498db;
    --color-success: #28a745;
    --color-warning: #ffc107;
    --color-error: #dc3545;
    --color-info: #17a2b8;

    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

[data-theme="dark"] {
    --color-primary: #667eea;
    --color-secondary: #764ba2;

    --bg-body: #0b1221;
    --bg-page: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --bg-container: rgba(17, 24, 39, 0.92);
    --bg-card: #111827;

    --text-primary: #e5e7eb;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --border-color: #1f2937;
    --shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-heavy: 0 15px 35px rgba(0, 0, 0, 0.4);

    --accent: #60a5fa;
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-info: #38bdf8;
}

/* ===== Body Variants ===== */
.body--gradient {
    background: var(--bg-page);
}

.body--flat {
    background: var(--bg-body);
    position: relative;
    overflow-x: hidden;
}

/* ===== Container ===== */
.container {
    max-width: 900px;
    width: calc(100% - 40px);
    margin: 0 auto 20px;
    background: var(--bg-container);
    border-radius: 20px;
    padding: 30px;
    box-shadow: var(--shadow);
    backdrop-filter: blur(10px);
    transition: background var(--transition-fast), box-shadow var(--transition-fast);
}

/* ===== Typography ===== */
h1, h2, h3 {
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

/* ===== Buttons ===== */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn:hover {
    transform: translateY(-2px);
}

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

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

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    background: var(--color-success);
    color: white;
}

.btn-success:hover {
    opacity: 0.9;
}

.btn-danger {
    background: var(--color-error);
    color: white;
}

.btn-danger:hover {
    opacity: 0.9;
}

/* ===== Form Elements ===== */
input, textarea, select {
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1em;
    font-family: inherit;
    background: var(--bg-container);
    color: var(--text-primary);
    transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}

input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

[data-theme="dark"] input:focus,
[data-theme="dark"] textarea:focus,
[data-theme="dark"] select:focus {
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.25);
}

/* ===== Upload Area ===== */
.upload-area {
    border: 3px dashed var(--color-primary);
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    margin-bottom: 30px;
    transition: all var(--transition-normal);
    cursor: pointer;
    color: var(--text-secondary);
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--color-secondary);
    background: rgba(102, 126, 234, 0.05);
    transform: translateY(-2px);
}

[data-theme="dark"] .upload-area:hover,
[data-theme="dark"] .upload-area.dragover {
    background: rgba(102, 126, 234, 0.15);
}

/* ===== Progress Bar ===== */
.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    width: 0%;
    transition: width var(--transition-normal);
}

/* ===== Status Messages ===== */
.status-success {
    background: rgba(40, 167, 69, 0.15);
    border: 1px solid var(--color-success);
    color: var(--color-success);
    padding: 10px 15px;
    border-radius: 8px;
}

.status-warning {
    background: rgba(255, 193, 7, 0.15);
    border: 1px solid var(--color-warning);
    color: #856404;
    padding: 10px 15px;
    border-radius: 8px;
}

[data-theme="dark"] .status-warning {
    color: var(--color-warning);
}

.status-error {
    background: rgba(220, 53, 69, 0.15);
    border: 1px solid var(--color-error);
    color: var(--color-error);
    padding: 10px 15px;
    border-radius: 8px;
}

.status-info {
    background: rgba(23, 162, 184, 0.15);
    border: 1px solid var(--color-info);
    color: var(--color-info);
    padding: 10px 15px;
    border-radius: 8px;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
    position: relative;
    width: 70px;
    height: 36px;
    background: var(--border-color);
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    overflow: hidden;
    flex-shrink: 0;
}

.theme-toggle:hover {
    background: #d0d0d0;
    transform: translateY(-1px);
}

.theme-toggle:active {
    transform: translateY(0);
}

[data-theme="dark"] .theme-toggle {
    background: #1f2937;
}

[data-theme="dark"] .theme-toggle:hover {
    background: #273447;
}

.theme-toggle-slider {
    position: absolute;
    top: 3px;
    left: 3px;
    width: 30px;
    height: 30px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] .theme-toggle-slider {
    transform: translateX(34px);
    background: #111827;
    color: #f8fafc;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

/* ===== Toolbar ===== */
.toolbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    margin-bottom: 15px;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    transition: background var(--transition-fast), border-color var(--transition-fast);
}
[data-theme="dark"] .toolbar {
    background: rgba(17, 24, 39, 0.85);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}
.toolbar__back { color: var(--text-primary); text-decoration: none; font-weight: 600; font-size: 0.95em; white-space: nowrap; transition: color var(--transition-fast); }
.toolbar__back:hover { color: var(--accent); }
.toolbar__title {
    flex: 1;
    text-align: center;
    font-weight: 700;
    font-size: 0.95em;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    min-width: 0;
    padding: 0 10px;
    transition: color var(--transition-fast);
}
.toolbar__lang { display: flex; gap: 6px; align-items: center; }
.toolbar__lang-btn { background: none; border: 1px solid var(--border-color); padding: 4px 10px; border-radius: 16px; cursor: pointer; font-size: 0.85em; transition: all var(--transition-fast); color: var(--text-primary); line-height: 1; }
.toolbar__lang-btn.active { background: var(--accent); color: white; border-color: var(--accent); }
.toolbar__lang-btn:hover:not(.active) { background: rgba(52, 152, 219, 0.1); }
[data-theme="dark"] .toolbar__lang-btn:hover:not(.active) { background: rgba(96, 165, 250, 0.15); }

@media (max-width: 480px) {
    .toolbar { padding: 8px 12px; gap: 6px; margin-bottom: 10px; }
    .toolbar__back { font-size: 0.85em; }
    .toolbar__title { font-size: 0.75em; padding: 0 4px; }
    .toolbar__lang-btn { padding: 3px 8px; font-size: 0.8em; }
}

/* ===== Copy Button ===== */
.copy-btn {
    background: var(--color-success);
    color: white;
    border: none;
    padding: 6px 14px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85em;
    transition: all var(--transition-fast);
}

.copy-btn:hover {
    opacity: 0.85;
    transform: translateY(-1px);
}

/* ===== Card ===== */
.card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow-light);
    transition: all var(--transition-normal);
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-heavy);
}

/* ===== Utilities ===== */
.hidden {
    display: none;
}

.text-center {
    text-align: center;
}

.text-mono {
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .container {
        width: calc(100% - 20px);
        padding: 20px;
        border-radius: 15px;
    }

    h1 {
        font-size: 1.8em;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 15px;
        border-radius: 12px;
    }

    h1 {
        font-size: 1.5em;
    }
}