/* ===== Root Variables ===== */
:root {
    --bg-primary: #0b0b1a;
    --bg-secondary: #12122a;
    --surface: rgba(255, 255, 255, 0.04);
    --surface-hover: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.08);
    --text-primary: #f0f0f5;
    --text-secondary: rgba(240, 240, 245, 0.55);
    --text-muted: rgba(240, 240, 245, 0.3);

    /* Accent colors */
    --focus-color: #ff6b6b;
    --focus-glow: rgba(255, 107, 107, 0.3);
    --focus-bg: rgba(255, 107, 107, 0.08);
    --short-break-color: #6bc5ff;
    --short-break-glow: rgba(107, 197, 255, 0.3);
    --short-break-bg: rgba(107, 197, 255, 0.08);
    --long-break-color: #a78bfa;
    --long-break-glow: rgba(167, 139, 250, 0.3);
    --long-break-bg: rgba(167, 139, 250, 0.08);

    /* Active accent (defaults to focus) */
    --accent: var(--focus-color);
    --accent-glow: var(--focus-glow);
    --accent-bg: var(--focus-bg);

    /* Ring */
    --ring-circumference: 659.73;

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

/* ===== State themes ===== */
body.state-focus {
    --accent: var(--focus-color);
    --accent-glow: var(--focus-glow);
    --accent-bg: var(--focus-bg);
}
body.state-short-break {
    --accent: var(--short-break-color);
    --accent-glow: var(--short-break-glow);
    --accent-bg: var(--short-break-bg);
}
body.state-long-break {
    --accent: var(--long-break-color);
    --accent-glow: var(--long-break-glow);
    --accent-bg: var(--long-break-bg);
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ===== Ambient Background Blobs ===== */
.ambient-blob {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.35;
    pointer-events: none;
    z-index: 0;
    transition: background 1.5s ease;
}
.blob-1 {
    width: 500px;
    height: 500px;
    background: var(--accent);
    top: -150px;
    left: -100px;
    animation: blob-float 20s ease-in-out infinite alternate;
}
.blob-2 {
    width: 400px;
    height: 400px;
    background: var(--long-break-color);
    bottom: -100px;
    right: -100px;
    animation: blob-float 25s ease-in-out infinite alternate-reverse;
}
.blob-3 {
    width: 300px;
    height: 300px;
    background: var(--short-break-color);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: blob-float 18s ease-in-out infinite alternate;
}

@keyframes blob-float {
    0%   { transform: translate(0, 0) scale(1); }
    33%  { transform: translate(30px, -40px) scale(1.05); }
    66%  { transform: translate(-20px, 20px) scale(0.95); }
    100% { transform: translate(10px, -10px) scale(1.02); }
}

/* ===== App Container ===== */
#app {
    position: relative;
    z-index: 1;
    max-width: 480px;
    margin: 0 auto;
    padding: 24px 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    animation: fade-in 0.6s var(--ease-out);
}

@keyframes fade-in {
    from { opacity: 0; transform: translateY(16px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ===== Header ===== */
.app-header {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 16px;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}
.logo-icon {
    width: 32px;
    height: 32px;
    filter: drop-shadow(0 0 8px var(--accent-glow));
    transition: filter 0.5s ease;
}
.logo h1 {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text-primary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.icon-btn {
    background: var(--surface);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    width: 40px;
    height: 40px;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: all 0.25s var(--ease-out);
}
.icon-btn:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
    transform: rotate(45deg);
}
.icon-btn.active {
    background: var(--accent-bg);
    color: var(--accent);
    border-color: var(--accent);
}

/* ===== Settings Panel ===== */
.settings-panel {
    width: 100%;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s var(--ease-out), padding 0.5s var(--ease-out), opacity 0.3s ease;
    opacity: 0;
    background: var(--surface);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    margin-bottom: 0;
}
.settings-panel.open {
    max-height: 300px;
    opacity: 1;
    padding: 20px;
    margin-bottom: 20px;
}
.settings-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.setting-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}
.setting-item label {
    font-size: 0.72rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
}
.number-input {
    display: flex;
    align-items: center;
    gap: 4px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    padding: 4px;
}
.number-input input {
    width: 44px;
    text-align: center;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    font-weight: 600;
    outline: none;
    -moz-appearance: textfield;
}
.number-input input::-webkit-outer-spin-button,
.number-input input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
.num-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    width: 28px;
    height: 28px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}
.num-btn:hover {
    background: var(--accent-bg);
    color: var(--accent);
}
.setting-unit {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ===== Timer Card ===== */
.timer-card {
    width: 100%;
    background: var(--surface);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    padding: 32px 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 28px;
    box-shadow:
        0 4px 30px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

/* State Tabs */
.state-tabs {
    display: flex;
    gap: 4px;
    background: rgba(255, 255, 255, 0.03);
    padding: 4px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}
.state-tab {
    padding: 8px 16px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
    white-space: nowrap;
}
.state-tab:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.04);
}
.state-tab.active {
    background: var(--accent-bg);
    color: var(--accent);
    box-shadow: 0 0 12px var(--accent-glow);
}

/* Timer Ring */
.timer-ring-container {
    position: relative;
    width: 220px;
    height: 220px;
}
.timer-ring {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}
.ring-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.05);
    stroke-width: 6;
}
.ring-progress {
    fill: none;
    stroke: var(--accent);
    stroke-width: 6;
    stroke-linecap: round;
    stroke-dasharray: var(--ring-circumference);
    stroke-dashoffset: 0;
    transition: stroke-dashoffset 1s linear, stroke 0.5s ease;
    filter: drop-shadow(0 0 8px var(--accent-glow));
}
.timer-display {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
}
.timer-text {
    font-family: 'JetBrains Mono', monospace;
    font-size: 3rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    text-shadow: 0 0 24px var(--accent-glow);
    transition: text-shadow 0.5s ease;
}
.state-label {
    font-size: 0.78rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--accent);
    transition: color 0.5s ease;
}

/* ===== Controls ===== */
.controls {
    display: flex;
    align-items: center;
    gap: 16px;
}
.control-btn {
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.3s var(--ease-out);
    font-size: 1.2rem;
}
.control-btn.primary {
    width: 64px;
    height: 64px;
    background: var(--accent);
    color: var(--bg-primary);
    font-size: 1.5rem;
    box-shadow: 0 4px 20px var(--accent-glow);
}
.control-btn.primary:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 30px var(--accent-glow);
}
.control-btn.primary:active {
    transform: scale(0.95);
}
.control-btn.secondary {
    width: 44px;
    height: 44px;
    background: var(--surface);
    color: var(--text-secondary);
    border: 1px solid var(--glass-border);
}
.control-btn.secondary:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
    transform: scale(1.08);
}

/* ===== Session Dots ===== */
.session-dots {
    display: flex;
    gap: 10px;
    align-items: center;
}
.session-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: 1.5px solid rgba(255, 255, 255, 0.15);
    transition: all 0.4s var(--ease-out);
}
.session-dot.completed {
    background: var(--accent);
    border-color: var(--accent);
    box-shadow: 0 0 10px var(--accent-glow);
    animation: dot-pop 0.4s var(--ease-out);
}

@keyframes dot-pop {
    0%   { transform: scale(0.5); }
    60%  { transform: scale(1.4); }
    100% { transform: scale(1); }
}

/* ===== Footer ===== */
.app-footer {
    margin-top: auto;
    padding-top: 32px;
    text-align: center;
}
.app-footer p {
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

/* ===== Pulse animation for state change ===== */
@keyframes pulse-ring {
    0%   { box-shadow: 0 0 0 0 var(--accent-glow); }
    70%  { box-shadow: 0 0 0 20px transparent; }
    100% { box-shadow: 0 0 0 0 transparent; }
}
.timer-card.pulse {
    animation: pulse-ring 0.8s ease-out;
}

/* ===== Responsive ===== */
@media (max-width: 520px) {
    #app {
        padding: 16px 14px;
    }
    .timer-card {
        padding: 24px 16px;
        border-radius: 20px;
    }
    .timer-ring-container {
        width: 180px;
        height: 180px;
    }
    .timer-text {
        font-size: 2.5rem;
    }
    .state-tabs {
        flex-wrap: wrap;
        justify-content: center;
    }
    .state-tab {
        padding: 6px 12px;
        font-size: 0.72rem;
    }
    .settings-grid {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }
    .control-btn.primary {
        width: 56px;
        height: 56px;
        font-size: 1.3rem;
    }
    .control-btn.secondary {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
    .ambient-blob {
        filter: blur(80px);
        opacity: 0.25;
    }
    .blob-1 { width: 300px; height: 300px; }
    .blob-2 { width: 250px; height: 250px; }
    .blob-3 { width: 200px; height: 200px; }
}

@media (max-width: 360px) {
    .timer-ring-container {
        width: 150px;
        height: 150px;
    }
    .timer-text {
        font-size: 2rem;
    }
    .state-label {
        font-size: 0.68rem;
    }
    .settings-grid {
        grid-template-columns: 1fr;
    }
}