:root {
    --bg-color: #0F0A1E;
    --primary-color: #7C3AED;
    --primary-hover: #6D28D9;
    --secondary-color: #A78BFA;
    --accent-color: #EDE9FE;
    --text-color: #F3F4F6;
    --text-muted: #9CA3AF;
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-bg: rgba(30, 27, 46, 0.5);
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --border-radius: 16px;
    --transition: 0.3s ease;
}

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

body {
    background-color: var(--bg-color);
    background-image:
        radial-gradient(circle at 10% 20%, rgba(124, 58, 237, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(167, 139, 250, 0.1) 0%, transparent 40%);
    color: var(--text-color);
    font-family: var(--font-family);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    color: var(--primary-color);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.header-controls {
    display: flex;
    gap: 1rem;
}

.icon-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-muted);
    padding: 0.6rem;
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    transform: translateY(-2px);
}

/* Main Content */
.main-content {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

@media (max-width: 900px) {
    .main-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .app-container {
        height: auto;
    }
}

/* Timer Section */
.timer-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2rem;
}

.timer-wrapper {
    position: relative;
    width: 280px;
    height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.timer-ring {
    transform: rotate(-90deg);
    position: absolute;
    top: 0;
    left: 0;
}

.timer-ring-bg {
    fill: none;
    stroke: var(--glass-border);
    stroke-width: 10;
}

.timer-ring-progress {
    fill: none;
    stroke: var(--primary-color);
    stroke-width: 10;
    stroke-dasharray: 816; /* 2 * PI * 130 */
    stroke-dashoffset: 0; /* Starts full */
    stroke-linecap: round;
    transition: stroke-dashoffset 1s linear;
}

.timer-text {
    text-align: center;
    z-index: 10;
}

#time-display {
    font-size: 4rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    line-height: 1;
    margin-bottom: 0.25rem;
}

#mode-display {
    font-size: 1.1rem;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 600;
}

.timer-controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.primary-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 50%;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 10px 25px rgba(124, 58, 237, 0.4);
    transition: var(--transition);
}

.primary-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 15px 30px rgba(124, 58, 237, 0.5);
}

.secondary-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-color);
    border-radius: 50%;
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.secondary-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* Mixer Section */
.mixer-section {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2rem;
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
}

.mixer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.mixer-header h3 {
    font-size: 1.2rem;
    font-weight: 600;
}

.mute-btn {
    background: none;
    border: none;
    color: var(--secondary-color);
    font-size: 0.9rem;
    cursor: pointer;
    font-weight: 600;
}

.mixer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.25rem;
}

.sound-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: rgba(0, 0, 0, 0.2);
    padding: 1rem;
    border-radius: 16px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.sound-card:hover {
    border-color: rgba(255, 255, 255, 0.1);
    background: rgba(0, 0, 0, 0.3);
}

.sound-icon {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary-color);
}

.sound-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.sound-info span {
    font-size: 0.95rem;
    font-weight: 500;
}

.volume-slider {
    -webkit-appearance: none;
    width: 100%;
    height: 4px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 2px;
    outline: none;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--secondary-color);
    cursor: pointer;
    transition: var(--transition);
}

.volume-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--primary-color);
}

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 10, 30, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background: #1E1B2E;
    border: 1px solid var(--glass-border);
    padding: 2rem;
    border-radius: 24px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

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

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.close-modal {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

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

/* Settings Form */
.settings-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.form-group input {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    padding: 0.8rem;
    border-radius: 12px;
    color: var(--text-color);
    font-family: inherit;
    font-size: 1rem;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.full-width {
    width: 100%;
    border-radius: 12px;
    margin-top: 1rem;
    font-weight: 600;
    font-size: 1rem;
    height: 50px;
}

/* Stats */
.stats-summary {
    text-align: center;
    padding: 1rem 0 2rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.session-list {
    list-style: none;
    max-height: 200px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.session-list li {
    background: rgba(255, 255, 255, 0.05);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
}

.session-date {
    color: var(--text-muted);
}

/* Utilities */
.hidden {
    display: none !important;
}