:root {
    --color-bg: #d5e0f0;
    --color-bg-card: #fff;
    --color-bg-input: #fff;
    --color-text: #0f172a;
    --color-muted: #475569;
    --color-disabled: #94a3b8;
    --color-border: #cbd5e1;
    --color-tag-text: #334155;
    --color-primary: #1a73e8;
    --color-primary-tint: #e8f0fe;
    --color-primary-on: #fff;
    --transition: 0.15s;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #080c15;
        --color-bg-card: #1e293b;
        --color-bg-input: #1e293b;
        --color-text: #f1f5f9;
        --color-muted: #b8c5d6;
        --color-disabled: #64748b;
        --color-border: #475569;
        --color-tag-text: #e2e8f0;
        --color-primary: #6bb1ff;
        --color-primary-tint: #1e3a5f;
        --color-primary-on: #0f172a;
    }
    body {
        background: var(--color-bg);
        color: var(--color-text);
    }
}

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

html,
body {
    height: 100%;
}

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

/* Top navigation */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: var(--color-bg-card);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1rem;
    z-index: 100;
}

.top-nav-left {
    flex: 1;
    display: flex;
    align-items: center;
}

.nav-title {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 0;
}
.top-nav-right {
    display: flex;
    gap: 1rem;
}

.nav-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    color: var(--color-text);
    transition: color var(--transition);
    text-decoration: none;
}

.nav-icon:hover {
    color: var(--color-primary);
}

/* Body starts below navbar */
body.search-page {
    padding-top: 56px;
}

/* Hero section — inherits page background and text colour from theme. */
.hero {
    width: 100%;
    text-align: center;
    padding: 1.5rem 1rem;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.hero-subtitle {
    font-size: 1.05rem;
    opacity: 0.9;
    margin-bottom: 1rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

h1.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
}

/* Search bar */
.search-bar {
    width: 100%;
    max-width: 500px;
    margin: 0 auto 1rem;
    padding: 0 1rem;
}

.search-bar input {
    width: 100%;
    padding: 0.75rem 1.25rem;
    font-size: 1rem;
    border: none;
    border-radius: 8px;
    background: var(--color-bg-input);
    color: var(--color-text);
    transition: box-shadow var(--transition);
}

.search-bar input:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
}

.search-bar input::placeholder {
    color: var(--color-muted);
}

/* Autocomplete */

/* Mobile navigation dropdown */
#mobile-nav {
    display: none;
    position: fixed;
    top: 56px;
    right: 0.5rem;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: 0.5rem;
    z-index: 200;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
}
#mobile-nav.open {
    display: flex;
}
.autocomplete-list {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    right: 0;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    max-height: 300px;
    overflow-y: auto;
    z-index: 200;
}

.ac-item {
    padding: 0.75rem 1rem;
    color: var(--color-text);
    text-decoration: none;
    display: block;
    border-bottom: 1px solid var(--color-border);
    transition: background var(--transition);
}

.ac-item:last-child {
    border-bottom: none;
}
.ac-item:hover {
    background: var(--color-primary-tint);
}
.ac-item strong {
    font-weight: 600;
}
.ac-desc {
    color: var(--color-muted);
    font-size: 0.85rem;
}

/* Favorites bar */
.recent-bar {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto 1rem;
    padding: 0 2rem;
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.recent-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--color-muted);
    white-space: nowrap;
}

.recent-links {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.recent-chip,
.fav-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.8rem;
    background: var(--color-primary-tint);
    color: var(--color-primary);
    border-radius: 20px;
    font-size: 0.85rem;
    text-decoration: none;
    transition: all var(--transition);
}

.recent-chip:hover {
    background: var(--color-primary);
    color: white;
}

.fav-star {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    font-size: 1rem;
    padding: 0;
}

/* Tag bar with grouped layout — groups stack vertically; within each group
   the label sits above its pill row (so it reads as a collapsible accordion). */
.tag-bar {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 0 1.5rem;
}

.tag-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
}

.tag-group-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
    justify-content: center;
}

.tag-group-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--color-muted);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    text-align: center;
    /* Button reset so it visually matches the prior <div> while staying clickable. */
    background: transparent;
    border: 0;
    cursor: pointer;
    font-family: inherit;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
}

.tag-group-label::before {
    content: '\25B8'; /* ▸ collapsed */
    font-size: 0.7em;
    opacity: 0.7;
    display: inline-block;
    transition: transform 0.15s ease;
}

.tag-group-label.is-expanded::before {
    content: '\25BE'; /* ▾ expanded */
}

.tag-group-label:hover {
    color: var(--color-text);
}

.tag-pill {
    padding: 0.35rem 0.9rem;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1.5px solid currentColor;
    border-radius: 20px;
    /* Per-pill colour is set inline by JS based on the tag's category;
       these are fallbacks for pills rendered without that styling. */
    background: transparent;
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition);
    user-select: none;
    display: inline-block;
}

.tag-pill:hover {
    transform: scale(1.05);
}

.tag-pill.active {
    background: currentColor;
    color: var(--color-bg);
}

/* Card grid */
.container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem 1.5rem;
}

a.container {
    display: grid;
}

.container > a {
    text-decoration: none;
    color: inherit;
}

.container a {
    padding: 0.75rem;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    text-decoration: none;
    color: inherit;
}

.container a:hover {
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
    border-color: var(--color-primary);
    transform: translateY(-3px);
}

.card-name {
    font-weight: 600;
    margin-bottom: 0.3rem;
    font-size: 0.85rem;
    color: var(--color-text);
    display: block;
}

.card-desc {
    display: none;
}

.card-icons {
    display: flex;
    gap: 0.2rem;
    justify-content: center;
    align-items: center;
    margin-bottom: 0.4rem;
    flex-wrap: nowrap;
}

.card-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    justify-content: center;
}

.card-tag {
    font-size: 0.65rem;
    font-weight: bold;
    padding: 0.15rem 0.4rem;
    border: 1px solid currentColor;
    background: rgba(128, 128, 128, 0.1);
    border-radius: 4px;
    display: inline-block;
    transition: all var(--transition);
    cursor: default;
}

.card-tag:hover {
    background: rgba(128, 128, 128, 0.2);
}

.container a.hidden {
    display: none;
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--color-muted);
    display: none;
}

.empty-state.visible {
    display: block;
}

/* Suggest calculator */
.suggest-calc-link {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--color-primary-tint);
    color: var(--color-primary);
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition);
}

.suggest-calc-link:hover {
    background: var(--color-primary);
    color: white;
}

/* Breadcrumb (hide on search page) */
.breadcrumb {
    display: none;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 1.8rem;
    }

    .container {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
}

/* Dark mode adjustments */
/* Apply dark variables when user selects dark theme via JS */
[data-theme='dark'] {
    --color-bg: #080c15;
    --color-bg-card: #1e293b;
    --color-bg-input: #1e293b;
    --color-text: #f1f5f9;
    --color-muted: #94a3b8;
    --color-disabled: #475569;
    --color-border: #334155;
    --color-tag-text: #cbd5e1;
    --color-primary: #4da3ff;
    --color-primary-tint: #1e3a5f;
    --color-primary-on: #0f172a;
}

/* Body cascade for the manual data-theme override (the @media query already
   handles system-level prefers-color-scheme). */
[data-theme='dark'] body {
    background: var(--color-bg);
    color: var(--color-text);
}
#hamburger-btn {
    display: none;
}
@media (max-width: 768px) {
    .top-nav-right .nav-icon {
        display: none;
    }
    #hamburger-btn {
        display: inline-flex;
    }
}
@media (min-width: 768px) {
    #mobile-nav {
        display: none !important;
    }
}
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #080c15;
        --color-bg-card: #1e293b;
        --color-bg-input: #1e293b;
        --color-text: #f1f5f9;
        --color-muted: #b8c5d6;
        --color-disabled: #64748b;
        --color-border: #475569;
        --color-primary: #6bb1ff;
        --color-primary-tint: #1e3a5f;
        --color-primary-on: #0f172a;
    }
    .container a {
        background: var(--color-bg-card);
        border-color: var(--color-border);
    }
}