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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f4f4f1;
    color: #111;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
}

.app {
    width: 100%;
    max-width: 600px;
    min-height: 100vh;
    margin: auto;
    background: #f4f4f1;
    padding-bottom: 90px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 28px 22px 18px;
}

.greeting {
    font-size: 14px;
    color: #777;
    margin-bottom: 4px;
}

header h1 {
    font-size: 23px;
}

.profile {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: #111;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: 600;
}

main {
    padding: 10px 18px;
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

.hero {
    background: #111;
    color: white;
    padding: 25px;
    border-radius: 24px;
    margin-bottom: 28px;
}

.small-label {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1.5px;
    color: #888;
    margin-bottom: 10px;
}

.hero .small-label {
    color: #aaa;
}

.hero h2 {
    font-size: 28px;
    margin-bottom: 12px;
}

.task-description {
    color: #bbb;
    line-height: 1.5;
    font-size: 14px;
    margin-bottom: 20px;
}

.task-time {
    font-size: 15px;
    margin-bottom: 20px;
}

.primary-button {
    width: 100%;
    padding: 16px;
    border-radius: 14px;
    background: white;
    color: #111;
    font-size: 15px;
    font-weight: 700;
}

.secondary-button {
    width: 100%;
    padding: 15px;
    margin-top: 10px;
    border-radius: 14px;
    background: transparent;
    color: #777;
    font-size: 14px;
}

.section-header,
.page-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 20px 4px 14px;
}

.section-header h2,
.page-title h2 {
    font-size: 20px;
}

.section-header button {
    background: transparent;
    color: #777;
}

.task-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.task {
    background: white;
    border-radius: 16px;
    padding: 17px;
    display: flex;
    align-items: center;
    gap: 14px;
}

.task.completed {
    opacity: 0.55;
}

.task strong {
    font-size: 15px;
}

.task p {
    color: #888;
    font-size: 13px;
    margin-top: 4px;
}

.check {
    width: 22px;
    height: 22px;
    border: 2px solid #ccc;
    border-radius: 50%;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.completed .check {
    background: #111;
    border-color: #111;
    color: white;
    font-size: 12px;
}

.insight {
    background: #e8e8e3;
    border-radius: 18px;
    padding: 17px;
    margin-top: 20px;
    display: flex;
    gap: 12px;
}

.insight-icon {
    font-size: 20px;
}

.insight strong {
    font-size: 14px;
}

.insight p {
    color: #666;
    font-size: 13px;
    line-height: 1.5;
    margin-top: 5px;
}

.focus-container {
    text-align: center;
    padding-top: 50px;
}

.focus-container h2 {
    font-size: 28px;
    margin-bottom: 45px;
}

.timer {
    font-size: 70px;
    font-weight: 700;
    letter-spacing: -3px;
    margin-bottom: 15px;
}

.focus-message {
    color: #777;
    margin-bottom: 35px;
}

.back-button {
    background: transparent;
    color: #777;
    font-size: 14px;
}

.add-button {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #111;
    color: white;
    font-size: 24px;
}

.stats-card {
    background: #111;
    color: white;
    border-radius: 22px;
    padding: 25px;
    margin-bottom: 15px;
}

.stats-card .small-label {
    color: #aaa;
}

.big-number {
    font-size: 38px;
    font-weight: 700;
    margin: 10px 0;
}

.stats-card p:last-child {
    color: #aaa;
    font-size: 13px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.stats-grid div {
    background: white;
    border-radius: 16px;
    padding: 18px 10px;
    text-align: center;
}

.stats-grid strong {
    display: block;
    font-size: 22px;
}

.stats-grid span {
    display: block;
    color: #888;
    font-size: 11px;
    margin-top: 5px;
}

nav {
    position: fixed;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 600px;
    height: 75px;
    background: rgba(255, 255, 255, 0.95);
    border-top: 1px solid #ddd;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    z-index: 10;
}

.nav-button {
    background: transparent;
    color: #999;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 4px;
}

.nav-button span {
    font-size: 21px;
}

.nav-button small {
    font-size: 10px;
}

.nav-button.active {
    color: #111;
}

@media (min-width: 601px) {
    body {
        padding: 30px 0;
    }

    .app {
        border-radius: 25px;
        min-height: calc(100vh - 60px);
        box-shadow: 0 10px 50px rgba(0,0,0,0.08);
    }

    nav {
        bottom: 30px;
        border-radius: 0 0 25px 25px;
    }
}