/* iPhone 15 Safe Area Variables */
@supports (padding: max(0px)) {
    :root {
        --safe-area-top: max(env(safe-area-inset-top), 12px);
        --safe-area-bottom: max(env(safe-area-inset-bottom), 12px);
        --safe-area-left: max(env(safe-area-inset-left), 12px);
        --safe-area-right: max(env(safe-area-inset-right), 12px);
    }
}

/* Base Styles & Variables */
:root {
    /* Color Palette */
    --primary: #007AFF;
    --primary-dark: #0062CC;
    --secondary: #5AC8FA;
    --background: #F2F2F7;
    --surface: #FFFFFF;
    --surface-secondary: #F2F2F7;
    --text-primary: #000000;
    --text-secondary: #8E8E93;
    --border: #D1D1D6;
    --success: #34C759;
    --warning: #FF9500;
    --error: #FF3B30;
    
    /* Spacing */
    --spacing-xxs: 4px;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    
    /* Mobile styles */
    @supports (padding: max(0px)) {
        .sidebar {
            padding-top: calc(var(--spacing-lg) + env(safe-area-inset-top));
            padding-bottom: calc(var(--spacing-lg) + env(safe-area-inset-bottom));
        }
        
        .main-content {
            padding: calc(var(--spacing-md) + env(safe-area-inset-top)) 
                     calc(var(--spacing-md) + env(safe-area-inset-right)) 
                     calc(var(--spacing-md) + env(safe-area-inset-bottom)) 
                     var(--spacing-md);
        }
    }
    
    /* Border Radius */
    --border-radius-sm: 8px;
    --border-radius-md: 12px;
    --border-radius-lg: 20px;
    --border-radius-xl: 28px;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    :root {
        --background: #000000;
        --surface: #1C1C1E;
        --surface-secondary: #2C2C2E;
        --text-primary: #FFFFFF;
        --text-secondary: #8E8E93;
        --border: #38383A;
    }
}

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

html {
    font-size: 16px;
    height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.5;
    height: 100%;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

#app {
    height: 100%;
}

/* Layout */
.app-container {
    display: flex;
    min-height: 100vh;
    position: relative;
}

/* iPhone 15 specific styles */
@supports (padding: max(0px)) {
    body {
        padding: env(safe-area-inset-top) env(safe-area-inset-right) 
                 env(safe-area-inset-bottom) env(safe-area-inset-left);
    }
    
    .app-container {
        padding-top: env(safe-area-inset-top);
        padding-bottom: env(safe-area-inset-bottom);
    }
    
    .sidebar {
        padding-top: calc(var(--spacing-lg) + env(safe-area-inset-top));
        padding-bottom: calc(var(--spacing-lg) + env(safe-area-inset-bottom));
    }
    
    .main-content {
        padding: calc(var(--spacing-lg) + env(safe-area-inset-top)) 
                 calc(var(--spacing-lg) + env(safe-area-inset-right)) 
                 calc(var(--spacing-lg) + env(safe-area-inset-bottom)) 
                 calc(260px + var(--spacing-lg) + env(safe-area-inset-left));
    }
}

/* Sidebar */
.sidebar {
    width: 260px;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-right: 1px solid rgba(255, 255, 255, 0.2);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100%;
    z-index: 100;
    transition: transform 0.3s ease, width 0.3s ease;
    box-shadow: var(--shadow-sm);
}

@media (max-width: 1024px) {
    .sidebar {
        transform: translateX(-100%);
        width: 280px;
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
}

.logo {
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary);
}

.logo i {
    margin-right: var(--spacing-sm);
    font-size: 1.8rem;
}

.nav-links {
    list-style: none;
    flex: 1;
}

.nav-links li {
    margin-bottom: var(--spacing-xs);
    border-radius: var(--border-radius-md);
    transition: background-color var(--transition-fast);
}

.nav-links li:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.nav-links li.active {
    background-color: var(--primary);
}

.nav-links li.active a {
    color: white;
}

.nav-links a {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    border-radius: var(--border-radius-md);
}

.nav-links i {
    margin-right: var(--spacing-sm);
    font-size: 1.1rem;
    width: 24px;
    text-align: center;
}

/* Frequency Input */
.freq-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-md);
    font-size: 1rem;
    background-color: var(--surface);
    color: var(--text-primary);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.freq-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 260px;
    padding: var(--spacing-lg);
    transition: margin-left 0.3s ease;
    max-width: calc(100% - 260px);
}

@media (max-width: 1024px) {
    .main-content {
        margin-left: 0;
        max-width: 100%;
        padding: var(--spacing-md);
    }
}

.content-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.content-header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
}

.header-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Cards */
.card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.card h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-md);
    font-weight: 500;
    font-size: 0.9rem;
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    gap: var(--spacing-xs);
    white-space: nowrap;
}

.btn i {
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

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

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

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: 50%;
}

/* Form Elements */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

input[type="text"],
input[type="number"],
input[type="email"],
input[type="password"],
select,
textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-md);
    font-size: 1rem;
    background-color: var(--surface);
    color: var(--text-primary);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input[type="text"]:focus,
input[type="number"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238E8E93' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--spacing-sm) center;
    padding-right: var(--spacing-xl);
}

textarea {
    min-height: 100px;
    resize: vertical;
}

/* Tabs */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

/* Program Editor */
.program-editor {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

@media (max-width: 1024px) {
    .program-editor {
        grid-template-columns: 1fr;
    }
}

.program-settings {
    grid-column: 1 / -1;
}

.exercise-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.exercise-item {
    background: var(--surface);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.exercise-item:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.exercise-info h4 {
    margin: 0 0 var(--spacing-xxs) 0;
    font-size: 1rem;
}

.exercise-meta {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.exercise-actions {
    display: flex;
    gap: var(--spacing-xs);
}

/* Metronome */
.metronome {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--surface-secondary);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-lg);
}

.metronome-display {
    margin-bottom: var(--spacing-md);
}

.beat {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-xs);
}

.bar {
    font-size: 1.5rem;
    color: var(--text-secondary);
    letter-spacing: 0.5em;
    margin-left: 0.25em;
}

.metronome-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
}

/* Tuner */
.tuner-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.tuner-display {
    position: relative;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
}

.note-display {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    display: flex;
    justify-content: center;
    align-items: baseline;
    gap: var(--spacing-xs);
}

#note {
    color: var(--primary);
}

#octave {
    font-size: 2rem;
    color: var(--text-secondary);
}

.cents-display {
    margin-bottom: var(--spacing-lg);
}

#cents {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-primary);
}

.cents-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.tuner-needle {
    height: 100px;
    position: relative;
    margin: var(--spacing-xl) 0;
}

.needle {
    position: absolute;
    top: 0;
    left: 50%;
    width: 4px;
    height: 100%;
    background-color: var(--primary);
    transform-origin: bottom center;
    transform: translateX(-50%) rotate(0deg);
    transition: transform 0.1s ease;
    border-radius: 2px;
}

.center-line {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background-color: var(--success);
    transform: translateY(-50%);
}

.tuner-scale {
    display: flex;
    justify-content: space-between;
    padding: 0 var(--spacing-lg);
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: var(--spacing-md);
}

.tuner-scale div {
    position: relative;
    width: 1px;
    height: 10px;
    background-color: var(--border);
    margin-top: 5px;
}

.tuner-scale div::after {
    content: attr(data-value);
    position: absolute;
    top: 15px;
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
}

.tuner-controls {
    max-width: 400px;
    margin: 0 auto;
}

/* Audio Analyzer */
.analyzer-container {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-lg);
}

@media (max-width: 1024px) {
    .analyzer-container {
        grid-template-columns: 1fr;
    }
}

.audio-inputs {
    margin-bottom: 0;
}

.audio-input-item {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border);
}

.audio-input-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.audio-input-item h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.input-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.file-upload {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--surface-secondary);
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

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

.file-upload i {
    margin-right: var(--spacing-xs);
}

.audio-preview {
    width: 100%;
    margin-top: var(--spacing-xs);
}

.visualization-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.viz-tab {
    padding: var(--spacing-xs) var(--spacing-md);
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--border-radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.viz-tab.active {
    background-color: var(--primary);
    color: white;
    border-color: var(--primary);
}

.visualization-container {
    position: relative;
    height: 300px;
    margin-bottom: var(--spacing-lg);
}

.visualization-container canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
}

.visualization-container canvas.active {
    display: block;
}

.analysis-controls {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.modal.show {
    display: flex;
    opacity: 1;
}

.modal-content {
    background: var(--surface);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    transform: translateY(20px);
    transition: transform var(--transition-normal);
    box-shadow: var(--shadow-lg);
}

.modal.show .modal-content {
    transform: translateY(0);
}

.close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color var(--transition-fast);
}

.close:hover {
    background-color: var(--surface-secondary);
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }

/* Responsive Helpers */
.hide-on-mobile {
    display: block;
}

@media (max-width: 768px) {
    .hide-on-mobile {
        display: none;
    }
    
    .btn-text {
        display: none;
    }
    
    .btn i {
        margin: 0;
    }
}

/* Animations */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.pulse {
    animation: pulse 1.5s infinite;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--surface-secondary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}