:root {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --primary-color: #ef4444;
    --primary-hover: #dc2626;
    --secondary-color: #334155;
    --secondary-hover: #475569;
    --pause-color: #eab308;
    --pause-hover: #ca8a04;
    --timer-bg: rgba(255, 255, 255, 0.05);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-image: radial-gradient(circle at 50% 0%, #1e293b 0%, #0f172a 70%);
}

.container {
    background: var(--timer-bg);
    padding: 3rem 4rem;
    border-radius: 24px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.container:hover {
    transform: translateY(-5px);
    box-shadow: 0 30px 60px -12px rgba(0, 0, 0, 0.6);
}

h1 {
    font-weight: 600;
    font-size: 1.25rem;
    margin-bottom: 2rem;
    color: #94a3b8;
    letter-spacing: 4px;
    text-transform: uppercase;
}

.settings {
    margin-bottom: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    color: #94a3b8;
}

.settings input {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: white;
    padding: 0.5rem;
    border-radius: 8px;
    width: 60px;
    text-align: center;
    font-size: 1rem;
    font-family: inherit;
    outline: none;
    transition: border-color 0.2s;
}

.settings input:focus {
    border-color: var(--primary-color);
}

.timer-wrapper {
    position: relative;
    width: 250px;
    height: 250px;
    margin: 0 auto 3rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

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

.progress-ring__circle {
    transition: stroke-dashoffset 1s linear;
}

.timer-display {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 0px;
    font-variant-numeric: tabular-nums;
    text-shadow: 0 0 30px rgba(239, 68, 68, 0.2);
    letter-spacing: -2px;
    z-index: 1;
}

.controls {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

.btn {
    font-family: inherit;
    font-size: 1.1rem;
    font-weight: 600;
    padding: 1rem 2.5rem;
    border: none;
    border-radius: 9999px;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    outline: none;
}

.btn:active {
    transform: scale(0.95);
}

.btn.primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 10px 15px -3px rgba(239, 68, 68, 0.4);
}

.btn.primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 10px 15px -3px rgba(239, 68, 68, 0.6);
}

.btn.primary.pause {
    background-color: var(--pause-color);
    box-shadow: 0 10px 15px -3px rgba(234, 179, 8, 0.3);
}

.btn.primary.pause:hover {
    background-color: var(--pause-hover);
    box-shadow: 0 10px 15px -3px rgba(234, 179, 8, 0.5);
}

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

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