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

:root {
    --bg: #f0f2f5;
    --bg-card: #fff;
    --bg-header: #fff;
    --text: #1a1a1a;
    --text-muted: #666;
    --text-footer: #888;
    --link: #2c5282;
    --link-hover: #1a365d;
    --border: #f0f2f5;
    --shadow: rgba(0, 0, 0, 0.06);
    --shadow-hover: rgba(0, 0, 0, 0.1);
    --shadow-header: rgba(0, 0, 0, 0.08);
    --bullet: #2c5282;
    --btn-bg: #2c5282;
    --btn-bg-hover: #1a365d;
    --btn-disabled: #a0aec0;
    --error-border: #e67e22;
    --error-text: #9a6700;
}

[data-theme="dark"] {
    --bg: #1a1a2e;
    --bg-card: #16213e;
    --bg-header: #0f3460;
    --text: #e0e0e0;
    --text-muted: #a0a0a0;
    --text-footer: #808080;
    --link: #64b5f6;
    --link-hover: #90caf9;
    --border: #253556;
    --shadow: rgba(0, 0, 0, 0.2);
    --shadow-hover: rgba(0, 0, 0, 0.4);
    --shadow-header: rgba(0, 0, 0, 0.3);
    --bullet: #64b5f6;
    --btn-bg: #1565c0;
    --btn-bg-hover: #1976d2;
    --btn-disabled: #455a64;
    --error-border: #f57c00;
    --error-text: #ffb74d;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: var(--bg-header);
    text-align: center;
    padding: 2rem 1rem 1.5rem;
    box-shadow: 0 1px 3px var(--shadow-header);
}

header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text);
}

.date {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin: 0;
}

.day-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 0.25rem;
}

.day-nav-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.25rem 0.6rem;
    cursor: pointer;
    font-size: 0.9rem;
    line-height: 1;
    color: var(--text);
    transition: border-color 0.2s, opacity 0.2s;
}

.day-nav-btn:hover:not(:disabled) {
    border-color: var(--text-muted);
}

.day-nav-btn:disabled {
    opacity: 0.3;
    cursor: default;
}

.header-controls {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.theme-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.3rem 0.5rem;
    cursor: pointer;
    font-size: 1.1rem;
    line-height: 1;
    color: var(--text);
    transition: border-color 0.2s;
}

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

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.25rem;
    padding: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    flex: 1;
}

.card {
    background: var(--bg-card);
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: 0 1px 4px var(--shadow);
    transition: box-shadow 0.2s;
}

.card:hover {
    box-shadow: 0 4px 12px var(--shadow-hover);
}

.card h2 {
    font-size: 1.15rem;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border);
}

.card h2 a {
    color: var(--link);
    text-decoration: none;
}

.card h2 a:hover {
    text-decoration: underline;
}

.card ul {
    list-style: none;
    padding: 0;
}

.card li {
    padding: 0.4rem 0;
    padding-left: 1.2rem;
    position: relative;
    font-size: 0.95rem;
}

.card li::before {
    content: "\2022";
    color: var(--bullet);
    font-weight: bold;
    position: absolute;
    left: 0;
}

.card--error {
    border-left: 4px solid var(--error-border);
}

.error-msg {
    color: var(--error-text);
    font-style: italic;
    padding: 0.5rem 0;
}

.extras {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border);
}

.extras p {
    color: var(--text-muted);
    font-size: 0.88rem;
    font-style: italic;
    padding: 0.15rem 0;
}

footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-footer);
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

footer button {
    background: var(--btn-bg);
    color: #fff;
    border: none;
    padding: 0.4rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: background 0.2s;
}

footer button:hover {
    background: var(--btn-bg-hover);
}

footer button:disabled {
    background: var(--btn-disabled);
    cursor: wait;
}

.version {
    color: var(--text-footer);
    font-size: 0.75rem;
    opacity: 0.6;
}

.install-banner[hidden] {
    display: none;
}

.install-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-top: 2px solid var(--btn-bg);
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    box-shadow: 0 -2px 8px var(--shadow);
    animation: bannerSlideUp 0.3s ease-out;
    z-index: 100;
}

.install-banner span {
    font-size: 0.95rem;
    font-weight: 500;
}

.install-banner-buttons {
    display: flex;
    gap: 0.5rem;
    flex-shrink: 0;
}

.install-banner button {
    background: var(--btn-bg);
    color: #fff;
    border: none;
    padding: 0.4rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: background 0.2s;
}

.install-banner button:hover {
    background: var(--btn-bg-hover);
}

.install-dismiss {
    background: transparent !important;
    color: var(--text-muted) !important;
    border: 1px solid var(--border) !important;
}

.install-dismiss:hover {
    border-color: var(--text-muted) !important;
    background: transparent !important;
}

@keyframes bannerSlideUp {
    from { transform: translateY(100%); }
    to { transform: translateY(0); }
}

@media (max-width: 700px) {
    .grid {
        grid-template-columns: 1fr;
        padding: 1rem;
    }

    header h1 {
        font-size: 1.5rem;
    }
}