:root {
    --bg: #f0f2f5;
    --card: #ffffff;
    --border: #e2e8f0;
    --text: #1e293b;
    --muted: #94a3b8;
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #eef2ff;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --item-height: 80px;
}

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

body {
    font-family:
        "Inter",
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        sans-serif;
    background: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 0 16px;
    overflow: hidden;
}

.app {
    width: 100%;
    max-width: 560px;
}

h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
    color: var(--text);
    text-align: center;
}

/* Form */
.new-task-form {
    padding: 20px;
}

input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    font-size: 15px;
    font-family: inherit;
    color: var(--text);
    background: var(--bg);
    transition:
        border-color var(--transition),
        box-shadow var(--transition);
}

input[type="text"]::placeholder {
    color: var(--muted);
}

input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
    background: white;
}

button {
    border: none;
    border-radius: var(--radius-sm);
    padding: 10px 16px;
    font-size: 14px;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
}

button:active {
    transform: scale(0.96);
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.4);
}

.input-row {
    display: flex;
    gap: 10px;
}

/* Viewport */
.task-viewport {
    position: relative;
    height: 70vh;
    overflow: hidden;
}

.selection-highlight {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: var(--item-height);
    transform: translateY(-50%);
    background: var(--primary-light);
    border: 2px solid var(--primary);
    border-radius: var(--radius-sm);
    pointer-events: none;
    z-index: 1;
    transition: opacity var(--transition);
}

.task-slider {
    position: relative;
    z-index: 2;
    transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateY(
        calc(
            35vh - var(--selected) * var(--item-height) - var(--item-height) / 2
        )
    );
}

.task-slider ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.task-slider li {
    display: flex;
    align-items: center;
    height: var(--item-height);
    padding: 0 14px;
    border-radius: var(--radius-sm);
    position: relative;
}

.task-title {
    flex: 1;
    font-size: 15px;
    line-height: 1.5;
}

.completed {
    text-decoration: line-through;
    color: var(--muted);
}

.task-actions {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    gap: 6px;
    opacity: 0;
    transition: opacity var(--transition);
    background: var(--primary-light);
    padding: 4px 8px;
    border-radius: 6px;
}

.task-actions button {
    font-size: 12px;
    padding: 5px 10px;
    border-radius: 6px;
}

.task-actions button[data-toggle] {
    background: var(--primary-light);
    color: var(--primary);
}

.task-actions button[data-toggle]:hover {
    background: var(--primary);
    color: white;
}

.task-actions button[data-delete] {
    background: transparent;
    color: var(--danger);
}

.task-actions button[data-delete]:hover {
    background: #fef2f2;
    color: var(--danger-hover);
}

.timestamp {
    font-size: 12px;
    color: var(--muted);
    white-space: nowrap;
    margin-right: 8px;
}

/* Section divider */
.task-slider li.section-empty {
    display: flex;
    justify-content: center;
    pointer-events: none;
    padding: 4px 0;
}

.muted {
    font-size: 14px;
    color: var(--muted);
}

.section-divider {
    height: var(--item-height);
    display: flex;
    align-items: center;
    pointer-events: none;
}

.completed-heading {
    font-size: 12px;
    font-weight: 600;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Fade edges */
.viewport-fade {
    position: absolute;
    left: 0;
    right: 0;
    height: 120px;
    pointer-events: none;
    z-index: 3;
}

.viewport-fade-top {
    top: 0;
    background: linear-gradient(to bottom, var(--bg) 0%, transparent 100%);
}

.viewport-fade-bottom {
    bottom: 0;
    background: linear-gradient(to top, var(--bg) 0%, transparent 100%);
}

/* Empty state */
.task-slider ul:empty::after {
    content: "Press i to add a task";
    display: flex;
    align-items: center;
    justify-content: center;
    height: var(--item-height);
    color: var(--muted);
    font-size: 14px;
}

.toast {
    position: fixed;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--text);
    color: white;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    opacity: 0;
    pointer-events: none;
    transition:
        opacity 0.2s ease,
        transform 0.2s ease;
    z-index: 100;
}

.toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}
@media (max-width: 500px) {
    .input-row {
        flex-direction: column;
    }
}

/* Offline banner */
.offline-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 8px 16px;
    background: var(--text);
    color: white;
    font-size: 13px;
    font-weight: 500;
    text-align: center;
    transform: translateY(-100%);
    transition: transform 0.2s ease;
    z-index: 200;
}

body.offline .offline-banner {
    transform: translateY(0);
}

/* App header with user bar */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.app-header h1 {
    margin-bottom: 0;
}

.user-bar {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-email {
    font-size: 13px;
    color: var(--muted);
}

.btn-signout {
    background: transparent;
    color: var(--muted);
    border: 1px solid var(--border);
    padding: 6px 12px;
    font-size: 13px;
}

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

/* Login page */
.login-card {
    width: 100%;
    max-width: 400px;
    background: var(--card);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-lg);
}

.login-card h1 {
    text-align: center;
    margin-bottom: 24px;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.login-form input[type="email"] {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border: 2px solid var(--border);
    font-size: 15px;
    font-family: inherit;
    color: var(--text);
    background: var(--bg);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.login-form input[type="email"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
    background: white;
}

.login-form button {
    width: 100%;
    padding: 12px;
    font-size: 15px;
}

.login-message {
    text-align: center;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.6;
}

.login-error {
    text-align: center;
    color: var(--danger);
    font-size: 14px;
    margin-bottom: 12px;
}