:root {
    --color-background-primary: #EAEAEA;
    --color-background-gridline: #FFFFFF;
    --color-text-primary: #0D0D0D;
    --color-text-secondary: #656565;
    --color-text-inverse: #FFFFFF;
    --color-accent-active: #0D0D0D;
    --color-accent-inactive: #D1D1D1;
    --color-button-primary-bg: #0D0D0D;
    --color-button-primary-text: #FFFFFF;
}

/* --- Base & Reset --- */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: var(--font-primary); background-color: var(--color-background-primary); color: var(--color-text-primary); -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
button { font-family: inherit; background: none; border: none; cursor: pointer; }
.container { display: flex; flex-direction: column; min-height: 100vh; max-width: 100vw; overflow-x: hidden; }
.hidden { display: none !important; }

/* --- 1. Global Header --- */
.global-header { display: flex; justify-content: space-between; align-items: center; padding: 2.5rem 3.5rem; position: absolute; width: 100%; z-index: 10; }
.logo { display: flex; align-items: center; gap: 0.75rem; }
.mode-selector { display: flex; gap: 2rem; }
.mode-btn { font-size: 1rem; font-weight: 600; letter-spacing: 0.05em; color: var(--color-text-secondary); transition: color 200ms ease; }
.mode-btn.active, .mode-btn:hover, .mode-btn:focus-visible { color: var(--color-text-primary); outline: none; }
.settings-btn { padding: 0.5rem; border-radius: 50%; transition: all 200ms ease-in-out; }
.settings-btn:hover, .settings-btn:focus-visible { opacity: 0.7; transform: scale(1.1); outline: 2px solid var(--color-text-primary); outline-offset: 2px; }
.settings-btn:active { transform: scale(0.95); }

/* --- View Management --- */
#app-views { flex-grow: 1; display: flex; flex-direction: column; }
.view { display: none; flex-direction: column; flex-grow: 1; animation: fadeIn 500ms ease forwards; }
.view.active-view { display: flex; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

/* --- 2. World Clock View --- */
#world-clock-view { min-height: 100vh; }
.time-panel { background-color: var(--color-background-primary); background-image: linear-gradient(var(--color-background-gridline) 1px, transparent 1px), linear-gradient(to right, var(--color-background-gridline) 1px, transparent 1px); background-size: 12.5% 100%; }
.main-clock-wrapper { padding: 0 3.5rem; padding-top: 8rem; }
.time-labels { display: grid; grid-template-columns: repeat(3, 1fr); padding-left: 2%; padding-bottom: 0.5rem; }
.time-labels span { font-size: 0.875rem; font-weight: 400; text-transform: lowercase; color: var(--color-text-secondary); }
.main-clock-display { display: grid; grid-template-columns: repeat(2, 1fr) 0.5fr repeat(2, 1fr) 0.5fr repeat(2, 1fr); align-items: center; justify-items: center; font-family: var(--font-display); font-weight: 700; line-height: 0.8; font-size: 20vw; color: var(--color-text-primary); overflow: hidden; }
.digit-container { overflow: hidden; position: relative; width: 100%; text-align: center; }
.digit-container span { display: inline-block; }
.separator { font-size: 10vw; font-weight: 700; transform: translateY(-0.1em); }
.timezone-selector-wrapper { padding: 1.5rem 3.5rem; border-top: 1px solid var(--color-background-gridline); border-bottom: 1px solid var(--color-background-gridline); }
.timezone-selector { display: grid; grid-template-columns: repeat(6, 1fr); text-align: center; }
.city-btn { font-family: var(--font-primary); padding: 1rem 0.5rem; position: relative; transition: color 200ms ease; }
.city-btn:focus-visible { outline: 2px solid var(--color-text-primary); outline-offset: -2px; border-radius: 4px; }
.city-btn::before { content: ''; position: absolute; top: 0; left: 50%; transform: translateX(-50%); width: 8px; height: 8px; border-radius: 50%; background-color: var(--color-accent-inactive); transition: all 200ms ease; }
.city-btn.active::before { background-color: var(--color-accent-active); }
.city-btn:hover::before { transform: translateX(-50%) scale(1.3); }
.city-btn .city-name { display: block; font-size: 1rem; font-weight: 500; color: var(--color-text-secondary); margin-bottom: 0.5rem; transition: color 200ms ease; }
.city-btn.active .city-name { color: var(--color-text-primary); }
.city-btn .city-time { display: block; font-family: var(--font-display); font-size: 1.25rem; font-weight: 700; color: var(--color-text-primary); }
.location-hero { flex-grow: 1; display: flex; flex-direction: column; justify-content: flex-end; padding: 2.5rem 3.5rem; background-size: cover; background-position: center; position: relative; color: var(--color-text-inverse); min-height: 40vh; transition: opacity 400ms ease-in-out; }
.location-hero::after { content: ''; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(0,0,0,0) 50%, rgba(0,0,0,0.5) 100%); z-index: 1; }
.location-info { position: relative; z-index: 2; display: flex; justify-content: space-between; align-items: flex-end; }
#location-name { font-size: 3.5rem; font-weight: 700; line-height: 1.1; text-transform: uppercase; max-width: 60%; }
.date { font-size: 1.25rem; font-weight: 400; text-align: right; }
.digit-flip { animation: flip-down 400ms cubic-bezier(0.22, 1, 0.36, 1); }
@keyframes flip-down { from { opacity: 0; transform: translateY(-20%); } to { opacity: 1; transform: translateY(0); } }
.fade-out { opacity: 0 !important; }

/* --- 3. Stopwatch View --- */
#stopwatch-view { align-items: center; justify-content: center; padding-top: 8rem; gap: 2rem; background: var(--color-background-primary); }
.stopwatch-display { font-size: clamp(4rem, 12vw, 8rem); grid: none; display: block; text-align: center; }
.stopwatch-display .ms { font-size: clamp(2rem, 6vw, 4rem); color: var(--color-text-secondary); }
.stopwatch-controls-laps { display: flex; gap: 4rem; align-items: flex-start; width: 80%; max-width: 1000px; }
.stopwatch-controls { display: flex; justify-content: center; gap: 1rem; flex: 1; }
.control-btn { padding: 0.75rem 1.5rem; font-size: 1.1rem; font-weight: 600; border-radius: 50px; transition: all 200ms ease; border: 2px solid var(--color-text-secondary); color: var(--color-text-secondary); }
.control-btn.primary { background: var(--color-button-primary-bg); color: var(--color-button-primary-text); border-color: var(--color-button-primary-bg); }
.control-btn:not(.primary):hover, .control-btn:not(.primary):focus-visible { border-color: var(--color-text-primary); color: var(--color-text-primary); }
.control-btn.primary:hover, .control-btn.primary:focus-visible { background-color: #333; }
.control-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.laps-list-container { flex: 1; height: 200px; overflow-y: auto; border-left: 1px solid #ccc; padding-left: 2rem; }
.laps-list { list-style: none; font-family: var(--font-display); }
.laps-list li { display: flex; justify-content: space-between; padding: 0.5rem 0; border-bottom: 1px solid #ddd; }
.laps-list li .lap-num { color: var(--color-text-secondary); }

/* --- 4. Timer View (Simplified) --- */
#timer-view { align-items: center; justify-content: center; padding: 8rem 2rem 2rem; gap: 2rem; background: var(--color-background-primary); }
.timer-inputs { display: flex; align-items: center; justify-content: center; font-family: var(--font-display); font-size: clamp(3rem, 10vw, 6rem); gap: 1rem; }
.timer-inputs input { width: 1.7em; font-size: inherit; font-family: inherit; text-align: center; border: none; background: transparent; border-bottom: 3px solid var(--color-text-secondary); color: var(--color-text-primary); -moz-appearance: textfield; }
.timer-inputs input::-webkit-outer-spin-button, .timer-inputs input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.timer-inputs input:focus { outline: none; border-bottom-color: var(--color-text-primary); }
.timer-input-separator { color: var(--color-text-secondary); }
.timer-input-labels { display: flex; justify-content: space-around; width: 65vw; max-width: 500px; color: var(--color-text-secondary); margin-top: -1rem; }
.timer-digital-display { font-size: clamp(4rem, 12vw, 8rem); display: block; text-align: center; font-family: var(--font-display); font-weight: 700; grid: none; }
.timer-digital-display.is-finished { animation: flash 1s infinite ease-in-out; }
@keyframes flash { 50% { color: #E74C3C; transform: scale(1.02); } }

/* --- 5. Developer Modal --- */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 100; display: flex; align-items: flex-end; justify-content: center; visibility: visible; opacity: 1; transition: visibility 0s, opacity 300ms ease; }
.modal-content { background: var(--color-background-primary); width: 100%; max-width: 500px; padding: 2.5rem 2rem 2rem; border-radius: 16px 16px 0 0; display: flex; flex-direction: column; gap: 1.5rem; transform: translateY(0); transition: transform 300ms cubic-bezier(0.16, 1, 0.3, 1); position: relative; }
.modal-overlay.hidden { visibility: hidden; opacity: 0; transition: visibility 0s 300ms, opacity 300ms ease; }
.modal-overlay.hidden .modal-content { transform: translateY(100%); }
.modal-header { display: flex; align-items: center; gap: 1rem; text-align: left; }
.dev-photo { width: 72px; height: 72px; border-radius: 50%; object-fit: cover; border: 2px solid var(--color-background-gridline); }
.dev-name { font-size: 1.5rem; font-weight: 700; }
.dev-title { font-size: 1rem; color: var(--color-text-secondary); }
.social-links { display: flex; justify-content: center; gap: 1.5rem; }
.social-links a { color: var(--color-text-secondary); transition: color 200ms ease; }
.social-links a:hover, .social-links a:focus-visible { color: var(--color-text-primary); }
.social-links svg { width: 24px; height: 24px; }
.dev-quote { font-style: italic; color: var(--color-text-secondary); padding: 1rem; border-top: 1px solid #ddd; margin-top: 0.5rem; }
.close-modal-btn { position: absolute; top: 1rem; right: 1rem; font-size: 2rem; color: var(--color-text-secondary); line-height: 1; }
.close-modal-btn:hover { color: var(--color-text-primary); }

/* --- Responsive (`<= 768px`) --- */
@media (max-width: 768px) {
    .global-header { padding: 1.5rem; flex-wrap: wrap; justify-content: center; row-gap: 1rem; }
    .mode-selector { order: 3; width: 100%; justify-content: center; gap: 1.5rem; }
    .logo { position: absolute; left: 1.5rem; top: 1.5rem; }
    .settings-btn { order: 2; position: absolute; right: 1.5rem; }
    .mode-btn { font-size: 0.875rem; }
    .main-clock-wrapper { padding: 0 1.5rem; padding-top: 8rem; }
    .main-clock-display { font-size: 26vw; }
    .separator { font-size: 13vw; }
    .time-labels { padding-left: 3%; }
    .timezone-selector-wrapper { padding: 1.5rem 0; }
    .timezone-selector { display: flex; overflow-x: auto; scroll-snap-type: x mandatory; padding: 0 1.5rem; -ms-overflow-style: none; scrollbar-width: none; }
    .timezone-selector::-webkit-scrollbar { display: none; }
    .city-btn { flex-shrink: 0; min-width: 110px; scroll-snap-align: start; }
    .location-hero { padding: 1.5rem; min-height: 50vh; }
    .location-info { flex-direction: column; align-items: flex-start; gap: 1rem; }
    #location-name { font-size: 2.5rem; max-width: 100%; }
    .date { font-size: 1rem; width: 100%; text-align: left; }
    #stopwatch-view, #timer-view { padding-top: 9rem; }
    .stopwatch-controls-laps { flex-direction: column; width: 90%; gap: 2rem; align-items: center; }
    .laps-list-container { width: 100%; border-left: none; padding-left: 0; border-top: 1px solid #ccc; padding-top: 1rem; }
    .timer-input-labels { width: 80vw; }
}