/* Theme variables */
:root {
    --color-bg: #f8f9fa;
    --color-bg-content: #ffffff;
    --color-bg-nav: #f8f9fa;
    --color-bg-code: #f1f3f5;
    --color-bg-hover: #e9ecef;
    --color-text: #333333;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;
    --color-link: #0066cc;
    --color-link-hover: #0052a3;
    --color-border: #eeeeee;
    --color-header-bg: #1a1a2e;
    --color-header-text: #ffffff;
    --color-accent: #ff9800;
    --color-highlight: #0066cc;
    --color-highlight-dark: #004080;
    --color-shadow: rgba(0, 0, 0, 0.1);
    --color-shadow-strong: rgba(0, 0, 0, 0.15);
}

/* Dark theme */
[data-theme="dark"] {
    --color-bg: #1a1a2e;
    --color-bg-content: #252542;
    --color-bg-nav: #1e1e36;
    --color-bg-code: #2d2d4a;
    --color-bg-hover: #3a3a5c;
    --color-text: #e4e4e7;
    --color-text-secondary: #a1a1aa;
    --color-text-muted: #71717a;
    --color-link: #60a5fa;
    --color-link-hover: #93c5fd;
    --color-border: #3f3f5c;
    --color-header-bg: #0f0f1a;
    --color-header-text: #ffffff;
    --color-accent: #fbbf24;
    --color-highlight: #3b82f6;
    --color-highlight-dark: #1d4ed8;
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-strong: rgba(0, 0, 0, 0.4);
}

/* Auto dark mode when no manual preference */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --color-bg: #1a1a2e;
        --color-bg-content: #252542;
        --color-bg-nav: #1e1e36;
        --color-bg-code: #2d2d4a;
        --color-bg-hover: #3a3a5c;
        --color-text: #e4e4e7;
        --color-text-secondary: #a1a1aa;
        --color-text-muted: #71717a;
        --color-link: #60a5fa;
        --color-link-hover: #93c5fd;
        --color-border: #3f3f5c;
        --color-header-bg: #0f0f1a;
        --color-header-text: #ffffff;
        --color-accent: #fbbf24;
        --color-highlight: #3b82f6;
        --color-highlight-dark: #1d4ed8;
        --color-shadow: rgba(0, 0, 0, 0.3);
        --color-shadow-strong: rgba(0, 0, 0, 0.4);
    }
}

/* Reset and base styles */
*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--color-text);
    margin: 0;
    padding: 0;
    background: var(--color-bg);
    transition: background-color 0.2s, color 0.2s;
}

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

a:hover {
    color: var(--color-link-hover);
    text-decoration: underline;
}

/* Header */
.site-header {
    background: var(--color-header-bg);
    color: var(--color-header-text);
    padding: 1rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-title {
    margin: 0;
    font-size: 1.5rem;
}

.site-title a {
    color: var(--color-header-text);
    text-decoration: none;
}

/* Header actions (theme toggle + calendar + RSS) */
.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Theme toggle */
.theme-toggle {
    background: transparent;
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    transition: background 0.2s, color 0.2s;
}

.theme-toggle:hover {
    background: var(--color-accent);
    color: var(--color-header-bg);
}

.theme-toggle svg {
    display: block;
    width: 20px;
    height: 20px;
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon,
.theme-toggle .icon-auto {
    display: none;
}

/* Show appropriate icon based on theme */
:root:not([data-theme]) .theme-toggle .icon-auto,
[data-theme="light"] .theme-toggle .icon-sun,
[data-theme="dark"] .theme-toggle .icon-moon {
    display: block;
}

.calendar-dropdown {
    position: relative;
}

.calendar-toggle {
    background: transparent;
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    transition: background 0.2s, color 0.2s;
}

.calendar-toggle:hover {
    background: var(--color-accent);
    color: var(--color-header-bg);
}

.calendar-toggle svg {
    display: block;
}

.calendar-popup {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: var(--color-bg-content);
    border-radius: 8px;
    box-shadow: 0 4px 20px var(--color-shadow-strong);
    padding: 1.25rem;
    min-width: 280px;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.2s, transform 0.2s, visibility 0.2s;
    z-index: 200;
}

.calendar-popup.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.rss-btn {
    background: transparent;
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.rss-btn:hover {
    background: var(--color-accent);
    color: var(--color-header-bg);
}

.rss-btn svg {
    display: block;
    width: 20px;
    height: 20px;
}

.rss-btn .rss-check {
    display: none;
}

.rss-btn.copied {
    background: #22c55e;
    border-color: #22c55e;
    color: white;
}

.rss-btn.copied .rss-icon {
    display: none;
}

.rss-btn.copied .rss-check {
    display: block;
}

/* Layout - single column now */
.layout {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    min-height: calc(100vh - 160px);
}

/* Calendar styling */
.calendar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.75rem;
}

.calendar-header h3 {
    margin: 0;
    font-size: 0.875rem;
    color: var(--color-text);
    font-weight: 600;
}

.calendar-nav-btn {
    background: none;
    border: none;
    padding: 0.25rem 0.5rem;
    cursor: pointer;
    color: var(--color-link);
    font-size: 1rem;
    border-radius: 4px;
    transition: background 0.2s;
}

.calendar-nav-btn:hover:not(:disabled) {
    background: var(--color-bg-hover);
}

.calendar-nav-btn:disabled {
    color: var(--color-text-muted);
    cursor: default;
}

.calendar-section h3,
.archive-section h3 {
    margin: 0 0 1rem 0;
    font-size: 0.875rem;
    color: var(--color-text);
    font-weight: 600;
}

.calendar {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
    table-layout: fixed;
}

.calendar th {
    padding: 0.5rem 0.25rem;
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    font-weight: 600;
    text-transform: uppercase;
}

.calendar td {
    padding: 0.25rem;
    text-align: center;
    font-size: 0.875rem;
}

.calendar td span {
    display: inline-block;
    width: 32px;
    height: 32px;
    line-height: 32px;
    color: var(--color-text-secondary);
}

.calendar td.has-entry a {
    display: inline-block;
    width: 32px;
    height: 32px;
    line-height: 32px;
    background: var(--color-highlight);
    color: white;
    border-radius: 50%;
    text-decoration: none;
    transition: background 0.2s;
}

.calendar td.has-entry a:hover {
    background: var(--color-link-hover);
}

.calendar td.current a {
    background: var(--color-highlight-dark);
    box-shadow: 0 0 0 2px var(--color-highlight);
}

/* Archive */
.archive-section {
    border-top: 1px solid var(--color-border);
    padding-top: 1rem;
    margin-top: 0.5rem;
}

.archive-month h4 {
    margin: 0 0 0.5rem 0;
    font-size: 0.875rem;
    color: var(--color-text);
}

.archive-month ul {
    list-style: none;
    padding: 0;
    margin: 0 0 1rem 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.archive-month li a {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background: var(--color-bg-hover);
    border-radius: 4px;
    font-size: 0.875rem;
}

.archive-month li a:hover {
    background: var(--color-border);
    text-decoration: none;
}

/* Main content */
.content {
    background: var(--color-bg-content);
    border-radius: 8px;
    padding: 2rem;
    box-shadow: 0 1px 3px var(--color-shadow);
    transition: background-color 0.2s;
}

/* Navigation */
.changelog-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--color-bg-nav);
    border-radius: 8px;
    margin-bottom: 2rem;
}

.nav-prev, .nav-next {
    min-width: 180px;
}

.nav-next {
    text-align: right;
}

.nav-current {
    font-weight: 600;
    color: var(--color-text);
}

.changelog-nav .disabled {
    color: var(--color-text-muted);
}

/* Changelog content */
.changelog-content {
    font-size: 1rem;
}

.changelog-content h1 {
    font-size: 1.75rem;
    margin: 0 0 1.5rem 0;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--color-border);
}

.changelog-content h2 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem 0;
    color: var(--color-text);
}

.changelog-content h3 {
    font-size: 1.25rem;
    margin: 1.5rem 0 0.75rem 0;
}

.changelog-content h4 {
    font-size: 1rem;
    margin: 1.25rem 0 0.5rem 0;
    color: var(--color-text-secondary);
}

.changelog-content ul {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
}

.changelog-content li {
    margin: 0.5rem 0;
}

.changelog-content hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: 2rem 0;
}

.changelog-content code {
    background: var(--color-bg-code);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.875em;
}

.changelog-content pre {
    background: var(--color-bg-code);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
}

.changelog-content pre code {
    background: none;
    padding: 0;
}

/* Footer */
.site-footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

.site-footer a {
    color: var(--color-link);
}

/* Responsive */
@media (max-width: 600px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .content {
        padding: 1rem;
    }

    .changelog-content h1 {
        font-size: 1.5rem;
    }

    .changelog-nav {
        flex-direction: column;
        gap: 0.75rem;
    }

    .nav-prev, .nav-next {
        min-width: auto;
        text-align: center;
    }

    .calendar-popup {
        right: -60px;
        min-width: 260px;
    }
}

/* Print styles */
@media print {
    .site-header,
    .changelog-nav,
    .site-footer {
        display: none;
    }

    .layout {
        display: block;
    }

    .content {
        box-shadow: none;
    }
}