:root {
    --color-bg: #0A1A15;
    --color-surface: rgba(16, 185, 129, 0.08);
    --color-surface-solid: #0E231C;
    --color-border: rgba(16, 185, 129, 0.15);
    --color-border-active: #10B981;
    --color-text: #D1F5E8;
    --color-text-secondary: #7DC8A8;
    --color-text-muted: #3D7A5E;
    --color-primary: #10B981;
    --color-primary-hover: #0D9668;
    --color-primary-glow: rgba(16, 185, 129, 0.3);
    --color-secondary: #34D399;
    --color-accent: #6EE7B7;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --radius: 16px;
    --radius-sm: 8px;
    --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

.bg-gradient {
    position: fixed;
    inset: 0;
    z-index: 0;
    background: radial-gradient(ellipse at 50% 50%, rgba(16, 185, 129, 0.06), transparent 70%);
    transition: background 3s ease;
    pointer-events: none;
}

.app-header {
    position: relative;
    z-index: 10;
    background: var(--color-surface-solid);
    border-bottom: 1px solid var(--color-border);
}

.header-inner {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 24px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--color-primary);
}

.logo h1 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--color-text);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.app-main {
    position: relative;
    z-index: 10;
    max-width: 900px;
    margin: 0 auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 18px;
    border-radius: var(--radius-sm);
    font-family: var(--font-sans);
    font-size: 0.87rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    box-shadow: 0 4px 16px var(--color-primary-glow);
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
}

.btn-ghost:hover {
    color: var(--color-text);
}

.btn-sm {
    padding: 5px 10px;
    font-size: 0.78rem;
}

.master-section {
    display: flex;
    align-items: center;
    gap: 12px;
}

.master-section label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
}

.master-section input[type="range"] {
    flex: 1;
    accent-color: var(--color-primary);
}

/* Sound Grid */
.sound-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
    gap: 14px;
}

.sound-card {
    background: var(--color-surface-solid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    cursor: pointer;
    transition: all 0.4s ease;
    backdrop-filter: blur(10px);
}

.sound-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.sound-card.active {
    border-color: var(--color-border-active);
    box-shadow: 0 0 20px var(--color-primary-glow);
}

.sound-card.active .sc-icon {
    filter: drop-shadow(0 0 8px var(--color-primary-glow));
}

.sc-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.sc-icon {
    font-size: 1.8rem;
}

.sc-toggle {
    width: 36px;
    height: 20px;
    border-radius: 999px;
    background: var(--color-border);
    border: none;
    cursor: pointer;
    position: relative;
    transition: background var(--transition);
}

.sc-toggle.on {
    background: var(--color-primary);
}

.sc-toggle::after {
    content: '';
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #fff;
    position: absolute;
    top: 2px;
    left: 2px;
    transition: transform var(--transition);
}

.sc-toggle.on::after {
    transform: translateX(16px);
}

.sc-name {
    font-size: 0.82rem;
    font-weight: 700;
}

.sc-slider {
    width: 100%;
    accent-color: var(--color-primary);
}

.sc-key {
    font-size: 0.6rem;
    color: var(--color-text-muted);
    text-align: right;
}

/* Presets */
.presets-section,
.timer-section {
    background: var(--color-surface-solid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 16px 20px;
}

.presets-section h2,
.timer-section h2 {
    font-size: 0.82rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.presets-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.preset-btn {
    padding: 7px 16px;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    background: transparent;
    cursor: pointer;
    transition: all var(--transition);
}

.preset-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.preset-btn.active {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

/* Timer */
.timer-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.timer-btn {
    padding: 6px 14px;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    background: transparent;
    cursor: pointer;
    transition: all var(--transition);
}

.timer-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.timer-btn.active {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

.timer-off {
    border-color: rgba(239, 68, 68, 0.3);
    color: #EF4444;
}

.timer-display {
    margin-top: 8px;
    font-size: 0.82rem;
    color: var(--color-accent);
    font-weight: 600;
}

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

.shortcuts-hint {
    font-size: 0.72rem;
    color: var(--color-text-muted);
}

.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    padding: 10px 24px;
    background: var(--color-primary);
    color: #fff;
    border-radius: var(--radius-sm);
    font-size: 0.87rem;
    font-weight: 600;
    box-shadow: 0 4px 24px var(--color-primary-glow);
    z-index: 200;
    animation: toastSlide 0.3s ease;
}

@keyframes toastSlide {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

@media (max-width: 600px) {
    .sound-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .app-main {
        padding: 16px;
        gap: 16px;
    }
}