/* ========================================
   NCM to MP3 Converter
   Functional Design System
   ======================================== */

/* ========================================
   1. Design Tokens - Systematic Scale
   ======================================== */
:root {
    /* Spacing Scale - 8px base unit (systematic) */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 24px;
    --space-6: 32px;
    --space-7: 48px;
    --space-8: 64px;
    --space-9: 96px;

    /* Color System - Neutral, Low-Saturation */
    --color-bg: #FAFAFA;
    --color-surface: #FFFFFF;
    --color-border: #E0E0E0;
    --color-border-strong: #BDBDBD;

    --color-text-primary: #212121;
    --color-text-secondary: #616161;
    --color-text-tertiary: #9E9E9E;
    --color-text-disabled: #BDBDBD;

    /* Functional Colors - Restrained */
    --color-success: #2E7D32;
    --color-warning: #F57C00;
    --color-error: #C62828;
    --color-primary: #FF0000;
    --color-processing: #1976D2;

    /* Interaction States */
    --color-hover: #F5F5F5;
    --color-active: #EEEEEE;
    --color-focus: #1976D2;

    /* Typography Scale - Rational Hierarchy */
    --text-xs: 11px;
    --text-sm: 13px;
    --text-base: 15px;
    --text-lg: 17px;
    --text-xl: 21px;
    --text-2xl: 28px;

    /* Transitions - Subtle, Functional */
    --transition-fast: 120ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Shadows - Minimal Elevation */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 2px 6px rgba(0, 0, 0, 0.08);

    /* Layout Grid */
    --container-max: 1024px;
    --content-max: 720px;
}

/* Dark Theme - Inverted Neutral Palette */
[data-theme="dark"] {
    --color-bg: #121212;
    --color-surface: #1E1E1E;
    --color-border: #2C2C2C;
    --color-border-strong: #404040;

    --color-text-primary: #E0E0E0;
    --color-text-secondary: #A0A0A0;
    --color-text-tertiary: #707070;
    --color-text-disabled: #505050;

    --color-hover: #252525;
    --color-active: #2A2A2A;
}

/* ========================================
   2. Base Reset - Systematic Foundation
   ======================================== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI',
        'Helvetica Neue', Arial, sans-serif,
        'Apple Color Emoji', 'Segoe UI Emoji';
    background: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color var(--transition-base),
        color var(--transition-base);
    font-weight: 400;
    letter-spacing: -0.01em;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

/* Force system fonts on all elements */
* {
    font-family: inherit;
}

/* ========================================
   3. Layout Structure - Grid-Based
   ======================================== */
.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.main {
    flex: 1;
    padding: var(--space-8) 0;
}

.container {
    width: 100%;
    max-width: var(--content-max);
    margin: 0 auto;
    padding: 0 var(--space-5);
}

/* ========================================
   5. Header Section - Information Hierarchy
   ======================================== */
.hero {
    display: flex;
    flex-direction: column;
    margin-bottom: var(--space-8);
    padding-bottom: var(--space-5);
    padding-top: var(--space-1);
    border-bottom: 1px solid var(--color-border);
}

.hero-header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.hero-logo {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
}

.hero-title {
    font-size: var(--text-2xl);
    font-weight: 600;
    margin: 0;
    color: var(--color-text-primary);
    letter-spacing: -0.03em;
}

.hero-subtitle {
    margin-top: var(--space-2);
    font-size: var(--text-base);
    color: var(--color-text-secondary);
    font-weight: 400;
    letter-spacing: 0;
}

/* ========================================
   6. Upload Area - Functional Zone
   ======================================== */
.upload-area {
    background: var(--color-surface);
    border: 2px dashed var(--color-border);
    padding: var(--space-7);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-bottom: var(--space-6);
}

.upload-area:hover {
    border-color: var(--color-border-strong);
    background: var(--color-hover);
}

.upload-area.dragover {
    border-color: var(--color-focus);
    background: var(--color-hover);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.upload-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-4);
}

.upload-icon svg {
    width: 24px;
    height: 24px;
}

.upload-text {
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
    margin-bottom: 2px;
}

.upload-hint {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-4);
}

.upload-badge {
    display: inline-block;
    padding: var(--space-1) var(--space-2);
    background: var(--color-bg);
    color: var(--color-text-tertiary);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.05em;
    border: 1px solid var(--color-border);
    text-transform: uppercase;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   7. File List - Structured Data Display
   ======================================== */
.file-list-container {
    display: none;
    margin-bottom: var(--space-6);
    overflow-x: hidden;
}

.file-list-container {
    display: block;
}

/* File List Items */
.file-list {
    list-style: none;
    max-height: 520px;
    overflow-y: auto;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.file-list::-webkit-scrollbar {
    width: 4px;
}

.file-list::-webkit-scrollbar-track {
    background: transparent;
}

.file-list::-webkit-scrollbar-thumb {
    background: var(--color-border);
}

.file-list::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-strong);
}

.file-item {
    display: flex;
    align-items: center;
    padding: var(--space-3) var(--space-4);
    gap: var(--space-4);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.file-item:last-child {
    margin-bottom: 0;
}

.file-item .file-icon {
    width: 48px;
    height: 48px;
    overflow: hidden;
    flex-shrink: 0;
}

.file-item .file-icon canvas {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.file-item .file-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.file-item .file-name {
    font-weight: 500;
    font-size: var(--text-sm);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin: 0;
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
    line-height: 1.4;
}

.file-item .file-meta {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    letter-spacing: 0;
}

.file-item .file-status {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    font-weight: 500;
    letter-spacing: 0;
    flex-shrink: 0;
}

.file-item .file-status.pending {
    color: var(--color-text-tertiary);
}

.file-item .file-status.processing {
    color: var(--color-processing);
}

.file-item .file-status.success {
    color: var(--color-success);
}

.file-item .file-status.error {
    color: var(--color-error);
}

.file-item .file-actions {
    display: flex;
    gap: var(--space-2);
    flex-shrink: 0;
}

.file-item .btn-icon {
    width: 32px;
    height: 32px;
}

.file-item .btn-icon svg {
    width: 14px;
    height: 14px;
}

/* ========================================
   8. Buttons - Systematic Controls
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: 0 var(--space-4);
    height: 36px;
    font-size: var(--text-sm);
    font-weight: 500;
    border: 1px solid var(--color-border);
    cursor: pointer;
    transition: all var(--transition-fast);
    background: var(--color-surface);
    color: var(--color-text-primary);
    letter-spacing: 0.01em;
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.btn svg {
    width: 14px;
    height: 14px;
}

.btn:hover {
    border-color: var(--color-border-strong);
    background: var(--color-hover);
}

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

.btn-primary {
    background: var(--color-text-primary);
    color: var(--color-surface);
    border-color: var(--color-text-primary);
}

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

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text-secondary);
    border-color: var(--color-border);
}

.btn-secondary:hover {
    border-color: var(--color-border-strong);
    color: var(--color-text-primary);
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    background: var(--color-surface);
    color: var(--color-text-secondary);
    border-color: var(--color-border);
}

.btn-icon:hover {
    border-color: var(--color-border-strong);
    color: var(--color-text-primary);
}

.btn-icon.success,
.btn.success {
    color: var(--color-success);
    border-color: var(--color-border);
}

.btn .file-meta {
    color: inherit;
    font-size: var(--text-xs);
    font-weight: 500;
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
}

/* ========================================
   9. Footer - Minimal Information
   ======================================== */
.footer {
    background: transparent;
    border-top: 1px solid var(--color-border);
    padding: var(--space-4);
    text-align: center;
}

.footer p {
    font-size: var(--text-xs);
    color: var(--color-text-tertiary);
    letter-spacing: 0;
}

.footer a {
    color: var(--color-text-tertiary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ========================================
   10. Notification System - Functional Feedback
   ======================================== */
.notification {
    position: fixed;
    top: var(--space-5);
    right: -400px;
    max-width: 360px;
    background: var(--color-surface);
    padding: var(--space-4);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: var(--space-3);
    z-index: 1000;
    transition: right var(--transition-base);
    border: 1px solid var(--color-border);
}

.notification.show {
    right: var(--space-4);
}

.notification-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.notification-icon svg {
    width: 100%;
    height: 100%;
}

.notification-message {
    flex: 1;
    font-size: var(--text-sm);
    font-weight: 400;
    color: var(--color-text-primary);
    line-height: 1.5;
    letter-spacing: 0;
}

.notification-success .notification-icon {
    color: var(--color-success);
}

.notification-error .notification-icon {
    color: var(--color-error);
}

.notification-warning .notification-icon {
    color: var(--color-warning);
}

.notification-info .notification-icon {
    color: var(--color-text-primary);
}

/* ========================================
   11. Responsive - Systematic Adaptation
   ======================================== */
@media (max-width: 768px) {
    .hero {
        align-items: center;
    }

    .file-list {
        max-height: 400px;
        margin: 0 calc(var(--space-5) * -1);
        padding: 0 var(--space-5);
    }

    .file-item .file-status {
        display: none;
    }
}

/* ========================================
   12. Audio Preview Modal
   ======================================== */
.audio-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.audio-modal-content {
    background: var(--color-surface);
    padding: var(--space-6);
    max-width: 400px;
    width: 90%;
    text-align: center;
    position: relative;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
}

.audio-modal-close {
    position: absolute;
    top: var(--space-3);
    right: var(--space-3);
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast);
}

.audio-modal-close:hover {
    background: var(--color-hover);
}

.audio-modal-close svg {
    width: 18px;
    height: 18px;
    color: var(--color-text-secondary);
}

.audio-modal-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-4);
}

.audio-modal-icon svg {
    width: 100%;
    height: 100%;
}

.audio-title {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: var(--space-4);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    padding: 0 var(--space-4);
}

#audio-player {
    width: 100%;
    margin-top: var(--space-2);
}

@media (max-width: 480px) {
    .btn span {
        display: none;
    }
}