/* ========================
   Global Styles & Reset
   ======================== */

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

:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --success: #10b981;
    --dark: #1f2937;
    --light: #f9fafb;
    --gray: #6b7280;
    --border: #e5e7eb;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Typography */
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition: all 0.3s ease;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--light);
    color: var(--dark);
    line-height: 1.6;
}

/* ========================
   Typography
   ======================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

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

/* ========================
   Layout
   ======================== */

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.navbar {
    background-color: var(--dark);
    color: white;
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand h1 {
    font-size: var(--font-size-2xl);
    margin: 0;
}

.navbar-menu {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-btn {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    font-size: var(--font-size-base);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 6px;
    transition: var(--transition);
    font-weight: var(--font-weight-medium);
}

.nav-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

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

.main-content {
    flex: 1;
    padding: var(--spacing-2xl);
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

/* ========================
   Views
   ======================== */

.view {
    display: none;
}

.view.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ========================
   Dashboard
   ======================== */

.dashboard-header {
    margin-bottom: var(--spacing-2xl);
}

.dashboard-header h2 {
    color: var(--dark);
}

.dashboard-header p {
    color: var(--gray);
    font-size: var(--font-size-lg);
    margin-bottom: 0;
}

.dashboard-grid {
    display: grid;
    gap: var(--spacing-2xl);
}

.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
}

.stat-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.stat-card h3 {
    color: var(--primary);
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-sm);
}

.stat-card p {
    color: var(--gray);
    font-size: var(--font-size-sm);
    margin: 0;
}

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

.recent-section {
    background: white;
    padding: var(--spacing-lg);
    border-radius: 10px;
    box-shadow: var(--shadow-md);
}

.courses-list {
    display: grid;
    gap: var(--spacing-lg);
}

.empty-state {
    text-align: center;
    color: var(--gray);
    padding: var(--spacing-2xl) 0;
    margin: 0;
}

/* ========================
   Courses Grid
   ======================== */

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.course-card {
    background: white;
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.course-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.course-card h3 {
    color: var(--dark);
    margin-top: 0;
}

.course-card p {
    color: var(--gray);
    font-size: var(--font-size-sm);
    flex: 1;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
    font-size: var(--font-size-sm);
    color: var(--gray);
}

.instrument-badge {
    display: inline-block;
    background-color: var(--primary-light);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 20px;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
}

/* ========================
   Buttons
   ======================== */

.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: 6px;
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: #404b5f;
    color: white;
}

.btn-secondary:hover {
    background-color: #6b7280;
}

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

.btn-danger:hover {
    background-color: #dc2626;
}

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

.btn-success:hover {
    background-color: #059669;
}

.btn:active {
    transform: scale(0.98);
}

.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
}

.btn-sm:active {
    transform: scale(0.96);
}

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

/* ========================
   Forms
   ======================== */

.form-group {
    margin-bottom: var(--spacing-lg);
}

label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: var(--font-weight-medium);
    color: var(--dark);
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="url"],
input[type="number"],
textarea,
select {
    width: 100%;
    padding: var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: inherit;
    font-size: var(--font-size-base);
    transition: var(--transition);
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
input[type="url"]:focus,
input[type="number"]:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

textarea {
    resize: vertical;
    font-family: 'Consolas', 'Monaco', monospace;
}

.form-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.rating-input {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.rating-input input {
    max-width: 100px;
}

/* ========================
   Modals
   ======================== */

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: white;
    padding: var(--spacing-2xl);
    border-radius: 10px;
    max-width: 500px;
    width: 90%;
    box-shadow: var(--shadow-xl);
    position: relative;
}

.close {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    font-size: var(--font-size-2xl);
    cursor: pointer;
    color: var(--gray);
    transition: var(--transition);
}

.close:hover {
    color: var(--dark);
}

.modal-close {
    margin-left: auto;
}

/* ========================
   Lesson Editor
   ======================== */

.lesson-editor-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    width: 100%;
}

.alphatab-preview {
    background: white;
    padding: var(--spacing-lg);
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    height: 570px;
    position: sticky;
    top: 100px;
    overflow: visible;
    flex: 0 0 auto;
    min-width: 0;
    max-width: 100%;
    display: flex;
    flex-direction: column;
}

.alphatab-preview h3 {
    margin-top: 0;
    margin-bottom: var(--spacing-md);
    flex-shrink: 0;
}

#alphatab-container {
    background-color: #f5f5f5;
    padding: var(--spacing-lg);
    border-radius: 6px;
    border: 1px solid var(--border);
    height: 500px;
    overflow: scroll !important;
    overflow-y: auto !important;
    overflow-x: hidden !important;
    box-sizing: border-box;
    width: 100%;
    flex: 1 1 auto;
    position: relative;
    contain: layout style;
}

/* ========================
   View Header
   ======================== */

.view-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-2xl);
}

.view-header h2 {
    margin: 0;
}

/* ========================
   Settings
   ======================== */

.settings-container {
    max-width: 800px;
}

.settings-section {
    background: white;
    padding: var(--spacing-lg);
    border-radius: 10px;
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-lg);
}

.settings-section h3 {
    margin-top: 0;
}

.settings-section p {
    color: var(--gray);
    margin-bottom: var(--spacing-lg);
}

#google-drive-status,
#ai-chat-url {
    margin-top: var(--spacing-lg);
}

#google-drive-status button {
    margin-right: var(--spacing-md);
}

/* ========================
   Toast Notifications
   ======================== */

.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.toast {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: 6px;
    font-weight: var(--font-weight-medium);
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease-out;
    max-width: 400px;
}

.toast.success {
    background-color: #10b981;
    color: white;
}

.toast.error {
    background-color: #ef4444;
    color: white;
}

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

.toast.warning {
    background-color: #f59e0b;
    color: white;
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}