:root {
    --primary-hue: 190;
    --primary-sat: 90%;
    --primary-light: 45%;

    --bg-color: hsl(220, 20%, 97%);
    --card-bg: rgba(255, 255, 255, 0.7);
    --text-main: hsl(220, 20%, 20%);
    --text-muted: hsl(220, 10%, 50%);
    --accent: hsl(var(--primary-hue), var(--primary-sat), var(--primary-light));
    --accent-glow: hsla(var(--primary-hue), var(--primary-sat), var(--primary-light), 0.3);

    --ring-bg: hsl(220, 20%, 90%);
    --ring-fg: var(--accent);

    --success: hsl(150, 60%, 45%);
    --warning: hsl(35, 90%, 55%);

    --font-family: 'Inter', sans-serif;

    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.05);

    transition: background-color 0.3s ease, color 0.3s ease;
}

[data-theme="dark"] {
    --bg-color: hsl(220, 20%, 10%);
    --card-bg: rgba(30, 35, 45, 0.6);
    --text-main: hsl(220, 20%, 95%);
    --text-muted: hsl(220, 10%, 65%);
    --accent: hsl(var(--primary-hue), 90%, 60%);
    --accent-glow: hsla(var(--primary-hue), 90%, 60%, 0.2);

    --ring-bg: hsl(220, 20%, 20%);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
    /* Prevent scrolling if possible */
}

/* Background Gradients */
body::before {
    content: '';
    position: absolute;
    width: 150vw;
    height: 150vh;
    background: radial-gradient(circle at 20% 20%, hsla(var(--primary-hue), 80%, 70%, 0.15), transparent 50%),
        radial-gradient(circle at 80% 80%, hsla(300, 80%, 70%, 0.15), transparent 50%);
    z-index: -1;
    top: -25vh;
    left: -25vw;
    pointer-events: none;
}

.app-container {
    width: 100%;
    max-width: 480px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
    /* Glassmorphism card for the main app container on larger screens */
    border-radius: 2rem;
}

@media (min-width: 500px) {
    .app-container {
        background: var(--card-bg);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        box-shadow: var(--shadow-md);
        border: 1px solid rgba(255, 255, 255, 0.1);
    }
}

header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-controls {
    display: flex;
    gap: 0.5rem;
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    letter-spacing: -0.05em;
    background: linear-gradient(135deg, var(--accent), #00e5ff);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-main);
    padding: 0.5rem;
    border-radius: 50%;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: rgba(128, 128, 128, 0.1);
}

.sun-icon {
    display: none;
}

.moon-icon {
    display: block;
}

[data-theme="light"] .sun-icon {
    display: none;
}

[data-theme="light"] .moon-icon {
    display: block;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

.sound-off-icon {
    display: none;
}

.sound-on-icon {
    display: block;
}

[data-sound="muted"] .sound-on-icon {
    display: none;
}

[data-sound="muted"] .sound-off-icon {
    display: block;
}

/* Timer Display */
.timer-display {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.progress-ring-container {
    position: relative;
    width: 300px;
    height: 300px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.progress-ring {
    transform: rotate(-90deg);
}

.progress-ring__circle-bg {
    stroke: var(--ring-bg);
}

.progress-ring__circle {
    stroke: var(--accent);
    stroke-dasharray: 816.8;
    /* 2 * PI * 130 */
    stroke-dashoffset: 0;
    /* Updated via JS */
    transition: stroke-dashoffset 0.1s linear, stroke 0.3s ease;
    filter: drop-shadow(0 0 10px var(--accent-glow));
    stroke-linecap: round;
}

.timer-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.time {
    font-size: 4rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    line-height: 1;
}

.status {
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-weight: 600;
    margin-top: 0.5rem;
    color: var(--text-muted);
}

/* Stats */
.stats-container {
    display: flex;
    width: 100%;
    justify-content: space-evenly;
    background: rgba(128, 128, 128, 0.05);
    padding: 1rem;
    border-radius: 1rem;
}

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

.stat-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-muted);
}

.stat-value {
    font-size: 1.25rem;
    font-weight: 700;
    margin-top: 0.25rem;
}

/* Controls */
.controls {
    display: flex;
    gap: 1rem;
    width: 100%;
    justify-content: center;
}

.btn {
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    padding: 0.8rem 2rem;
    border-radius: 100px;
    /* Pill shape */
    border: none;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.2s, background 0.2s;
}

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

.btn-primary {
    background: var(--accent);
    color: white;
    /* Always white on accent */
    box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary:hover {
    filter: brightness(1.1);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.btn-secondary {
    background: rgba(128, 128, 128, 0.1);
    color: var(--text-main);
}

.btn-secondary:hover:not(:disabled) {
    background: rgba(128, 128, 128, 0.2);
}

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

.btn-text {
    background: transparent;
    color: var(--text-muted);
    padding: 0.8rem 1.5rem;
}

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


/* Settings Modal */
.settings-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 1;
    pointer-events: all;
    transition: opacity 0.3s ease;
}

.settings-modal.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: -1;
}

.settings-content {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 1.5rem;
    width: 90%;
    max-width: 400px;
    box-shadow: var(--shadow-md);
    transform: translateY(0);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: 1px solid rgba(128, 128, 128, 0.1);
}

.settings-modal.hidden .settings-content {
    transform: translateY(20px);
}

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

.settings-header h3 {
    font-size: 1.5rem;
    margin: 0;
}

/* Utilities used by JS */

.text-work {
    color: var(--accent);
}

.text-rest {
    color: var(--success);
}

.stroke-work {
    stroke: var(--accent);
}

.stroke-rest {
    stroke: var(--success);
}