:root {
    --bg-color: hsl(240, 10%, 4%);
    --surface-glass: hsla(240, 5%, 8%, 0.6);
    --surface-glass-border: hsla(240, 5%, 20%, 0.3);
    --primary-color: hsl(264, 82%, 60%);
    --primary-glow: hsla(264, 82%, 60%, 0.4);
    --accent-color: hsl(190, 100%, 50%);
    --text-main: hsl(210, 15%, 95%);
    --text-muted: hsl(210, 10%, 70%);
    --glass-blur: blur(12px);
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-light {
    --bg-color: hsl(210, 20%, 98%);
    --surface-glass: hsla(210, 20%, 90%, 0.7);
    --surface-glass-border: hsla(210, 20%, 70%, 0.3);
    --text-main: hsl(240, 10%, 10%);
    --text-muted: hsl(240, 5%, 40%);
    --primary-glow: hsla(264, 82%, 60%, 0.2);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: Inter, system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 10% 20%, hsla(264, 82%, 15%, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, hsla(190, 100%, 10%, 0.1) 0%, transparent 40%);
    min-height: 100vh;
}

.theme-light body {
    background-image: 
        radial-gradient(circle at 10% 20%, hsla(264, 82%, 95%, 0.5) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, hsla(190, 100%, 95%, 0.5) 0%, transparent 40%);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition-smooth);
}

a:hover {
    color: var(--accent-color);
}

.glass-card {
    background: var(--surface-glass);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--surface-glass-border);
    border-radius: 16px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.btn-modern {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px var(--primary-glow);
    background: hsl(264, 82%, 65%);
}

.btn-secondary {
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: hsla(240, 5%, 20%, 0.5);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.nav-bar {
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-color);
    opacity: 0.95;
    backdrop-filter: blur(10px);
}

.search-input-modern {
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    border-radius: 12px;
    padding: 12px 20px;
    color: var(--text-main);
    width: 100%;
    outline: none;
    transition: var(--transition-smooth);
}

.search-input-modern:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px var(--primary-glow);
}

/* Animations */
@keyframes fade-in {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fade-in 0.5s ease forwards;
}

/* Toggle Switch */
.switch-modern {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}
.switch-modern input {
    opacity: 0;
    width: 0;
    height: 0;
}
.slider-modern {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    transition: .4s;
    border-radius: 24px;
}
.slider-modern:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 4px;
    bottom: 3px;
    background-color: var(--text-muted);
    transition: .4s;
    border-radius: 50%;
}
input:checked + .slider-modern {
    background-color: var(--primary-glow);
    border-color: var(--primary-color);
}
input:checked + .slider-modern:before {
    transform: translateX(20px);
    background-color: var(--primary-color);
    box-shadow: 0 0 10px var(--primary-glow);
}

/* Modal System */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(8px);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    transition: var(--transition-smooth);
}
.modal-overlay.active {
    display: flex;
    opacity: 1;
}
.modal-content {
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    padding: 30px;
    border-radius: 20px;
    position: relative;
    max-width: 90%;
    transform: scale(0.9);
    transition: var(--transition-smooth);
    text-align: center;
}
.modal-overlay.active .modal-content {
    transform: scale(1);
}
.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-muted);
}
.modal-close:hover {
    color: var(--primary-color);
}

/* Helper Classes */
.fade-in-margin-top { margin-top: 40px; }
.card-padding { padding: 30px; display: flex; flex-direction: column; }
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 30px; margin-bottom: 40px; }
.primary-top-border { border-top: 4px solid var(--primary-color); }
.accent-top-border { border-top: 4px solid var(--accent-color); }
.muted-text { color: var(--text-muted); }
.lead-text { max-width: 700px; margin: 0 auto; font-size: 1.1rem; }
.btn-full { width: 100%; }
.small-meta { font-size: 0.8rem; color: var(--text-muted); margin-top: 15px; text-align: center; }

/* Advanced Search Accordion */
.advanced-search-toggle {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin: 0 auto;
    padding: 8px 16px;
    transition: var(--transition-smooth);
    border-radius: 8px;
}

.advanced-search-toggle:hover {
    color: var(--primary-color);
    background: rgba(255, 255, 255, 0.05);
}

.advanced-search-toggle svg {
    transition: transform 0.3s ease;
}

.advanced-search-toggle.open svg {
    transform: rotate(180deg);
}

.advanced-search-container {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.4s ease, opacity 0.4s ease, padding 0.4s ease;
}

.advanced-search-container.open {
    max-height: 300px;
    padding-top: 25px;
    opacity: 1;
}

/* Segmented Engine Toggle */
.engine-toggle-container {
    display: flex;
    position: relative;
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    border-radius: 12px;
    padding: 4px;
    margin-bottom: 15px;
    width: fit-content;
}

.engine-toggle-container input[type="radio"] {
    display: none;
}

.engine-toggle-label {
    position: relative;
    z-index: 2;
    padding: 8px 24px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-smooth);
    border-radius: 8px;
    user-select: none;
    text-align: center;
    min-width: 120px;
}

.engine-toggle-container input[type="radio"]:checked + .engine-toggle-label {
    color: white;
}

.engine-toggle-slider {
    position: absolute;
    top: 4px;
    bottom: 4px;
    left: 4px;
    width: calc(50% - 4px);
    background: var(--primary-color);
    border-radius: 8px;
    transition: var(--transition-smooth);
    z-index: 1;
    box-shadow: 0 2px 10px var(--primary-glow);
}

#menu-engine-shiki:checked ~ .engine-toggle-slider,
#engine-shiki:checked ~ .engine-toggle-slider {
    transform: translateX(100%);
}

/* Settings Dropdown */
.settings-container {
    position: relative;
    display: flex;
    align-items: center;
}

.settings-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 8px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-smooth);
}

.settings-btn:hover, .settings-btn.active {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px var(--primary-glow);
    background: hsl(264, 82%, 65%);
}

.settings-btn-secondary {
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    color: var(--text-main);
}

.settings-btn-secondary:hover{
    background: hsla(240, 5%, 20%, 0.5);
}


.settings-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 10px;
    background: var(--surface-glass);
    border: 1px solid var(--surface-glass-border);
    border-radius: 16px;
    padding: 15px;
    min-width: 280px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.5);
    backdrop-filter: var(--glass-blur);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition-smooth);
    z-index: 100;
}

.settings-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.settings-menu-header {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--surface-glass-border);
}

.settings-item {
    display: flex;
    flex-direction: column;
    margin-bottom: 15px;
}

.settings-item:last-child {
    margin-bottom: 0;
}

.settings-label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.settings-toggle-btn {
    background: var(--surface-dark);
    border: 1px solid var(--surface-glass-border);
    color: var(--text-main);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition-smooth);
    width: 100%;
    text-align: left;
}

.settings-toggle-btn:hover {
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.05);
}

.settings-engine-toggle {
    width: 100%;
    margin-bottom: 0;
}

.settings-engine-toggle .engine-toggle-label {
    min-width: unset;
    flex: 1;
    padding: 6px 12px;
}

/* ---- Shared utility ---- */
.text-primary  { color: var(--primary-color); }
.text-accent   { color: var(--primary-color); }

/* ---- Guide Page ---- */
.guide-intro {
    text-align: center;
    margin-bottom: 50px;
}

.guide-title {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.guide-card-emoji {
    font-size: 2rem;
    margin-bottom: 15px;
}

.guide-card-title {
    margin-bottom: 15px;
}

.guide-card-desc {
    margin-bottom: 25px;
    flex-grow: 1;
}

.guide-steps-card {
    padding: 40px;
}

.guide-steps-header {
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.guide-steps-badge {
    background: var(--primary-glow);
    padding: 5px 12px;
    border-radius: 8px;
    font-size: 0.9rem;
}

.guide-steps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
}

.guide-step-number {
    color: var(--primary-color);
    font-size: 1.2rem;
    display: block;
    margin-bottom: 10px;
}

.guide-step-desc {
    font-size: 0.9rem;
}

.guide-back-link {
    margin-top: 40px;
    text-align: center;
}