/* --- Fonts --- */
@font-face {
    font-family: 'Inter';
    src: url('../fonts/Inter-Variable.ttf') format('truetype-variations');
    font-weight: 100 900;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Sans TC';
    src: url('../fonts/NotoSansTC-Variable.ttf') format('truetype-variations');
    font-weight: 100 900;
    font-style: normal;
    font-display: swap;
}

/* --- Tokens & Variables --- */
:root {
    --font-zh: 'Noto Sans TC', system-ui, -apple-system, sans-serif;
    --font-en: 'Inter', system-ui, -apple-system, sans-serif;

    /* Scroll Snapping (Sticky Feel) */
}

@media (min-width: 1024px) {
    html {
        scroll-snap-type: y mandatory;
        scroll-behavior: smooth;
    }
}

:root {

    /* Dark Theme (Default) */
    --bg-body: #0A0F1A;
    --bg-card: rgba(30, 41, 59, 0.4);
    --bg-glass: rgba(15, 23, 42, 0.75);

    --text-heading: #F8FAFC;
    --text-body: #CBD5E1;
    --text-muted: #94A3B8;

    --accent: #06B6D4;
    --accent-glow: rgba(6, 182, 212, 0.3);
    --border: rgba(255, 255, 255, 0.1);

    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    --glass-border: linear-gradient(to bottom right, rgba(255, 255, 255, 0.1), rgba(255, 255, 255, 0.02));

    --navbar-height: 5.5rem;
    --section-spacing: 8rem;
}

.light-theme {
    --bg-body: #F9FAFB;
    --bg-card: #FFFFFF;
    --bg-glass: rgba(255, 255, 255, 0.85);

    --text-heading: #0F172A;
    --text-body: #475569;
    --text-muted: #64748B;

    --accent: #0891B2;
    --accent-glow: rgba(8, 145, 178, 0.1);
    --border: rgba(0, 0, 0, 0.08);

    --card-shadow: 0 4px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
    --glass-border: linear-gradient(to bottom right, rgba(0, 0, 0, 0.05), rgba(0, 0, 0, 0.01));
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-body);
    color: var(--text-body);
    font-family: var(--font-en);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.4s cubic-bezier(0.4, 0, 0.2, 1), color 0.4s ease;
    overflow-x: hidden;
}

html[lang="zh-Hant"] body {
    font-family: var(--font-zh);
}

/* --- Typography --- */
h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--text-heading);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

p {
    margin-bottom: 1.5rem;
}

.text-accent {
    color: var(--accent);
}

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

/* --- Layout --- */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section-padding {
    padding: var(--section-spacing) 0;
}

@media (min-width: 1024px) {
    .section-full {
        min-height: 100vh;
        display: flex;
        flex-direction: column;
        justify-content: center;
        scroll-snap-align: start;
        scroll-snap-stop: always;
    }

    .section-footer-merge {
        justify-content: flex-start;
        padding-bottom: 0 !important;
    }
}

/* --- Components --- */

/* Navigation */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    background-color: transparent;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: 1px solid transparent;
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    color: white;
    /* Default for transparent state */
}

#navbar:not(.navbar-scrolled) .nav-link {
    color: rgba(255, 255, 255, 0.8);
}

#navbar:not(.navbar-scrolled) .nav-link:hover {
    color: white;
}

#navbar:not(.navbar-scrolled) .text-heading {
    color: white;
}

#navbar:not(.navbar-scrolled) .main-logo {
    background-color: white !important;
}

#navbar:not(.navbar-scrolled) .control-btn {
    color: white;
    border-color: rgba(255, 255, 255, 0.2);
}

#navbar:not(.navbar-scrolled) .hamburger-line {
    stroke: white;
}

#navbar.navbar-scrolled {
    height: 4.5rem;
    background-color: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    color: var(--text-heading);
}

.light-theme #navbar.navbar-scrolled .text-heading,
body.is-menu-open #navbar .text-heading {
    color: #4A5568 !important;
    /* Deep gray for brand text in light context */
}

body.is-menu-open #navbar .main-logo {
    background-color: var(--accent) !important;
}

body.is-menu-open #navbar .hamburger-line,
body.is-menu-open #navbar .control-btn svg,
.control-btn:hover .hamburger-line {
    stroke: #4A5568 !important;
    color: #4A5568 !important;
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.0625rem;
    transition: color 0.2s ease;
    padding: 0.5rem 0;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
}

/* Buttons */
.btn,
.btn-primary,
.btn-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 2rem;
    border-radius: 9999px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--accent);
    color: #FFFFFF;
}

.btn-primary:hover {
    transform: translateY(-2px);
    filter: brightness(1.1);
}

.btn-outline {
    border-color: var(--border);
    color: var(--text-heading);
    background-color: var(--bg-card);
}

.btn-outline:hover {
    background-color: var(--bg-glass);
    border-color: var(--accent);
    color: var(--accent);
}

/* Cards */
.glass-card {
    background-color: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: 1.5rem;
    padding: 2.5rem;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    position: relative;
}

.glass-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent);
    background-color: color-mix(in srgb, var(--bg-card) 70%, var(--bg-body));
}

/* Hero */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background-color: var(--bg-body);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background-image: url('../images/bgi.jpg');
    background-size: cover;
    background-position: center;
    filter: brightness(0.6);
    z-index: 0;
}

/* Removed light theme override for hero-bg to unify with dark theme */

.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to bottom,
            rgba(10, 15, 26, 0.3) 0%,
            rgba(10, 15, 26, 0.2) 50%,
            rgba(10, 15, 26, 0.3) 100%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 4vw, 2rem);
    font-weight: 700;
    letter-spacing: 0.1em;
    color: rgba(255, 255, 255, 0.9);
    margin-top: -1rem;
    margin-bottom: 2rem;
    text-transform: uppercase;
}

.hero h1 {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    margin-bottom: 1.5rem;
    color: #FFFFFF;
}

.hero p {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 2.5rem;
}

/* Control Buttons (Theme/Lang) */
.control-btn {
    height: 2.5rem;
    width: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.75rem;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s ease;
    -webkit-tap-highlight-color: transparent;
    outline: none !important;
}

.control-btn:hover,
.control-btn:focus,
.control-btn:focus-visible,
.control-btn:active {
    outline: none !important;
    box-shadow: none !important;
}

@media (hover: hover) {
    .control-btn:hover {
        border-color: var(--accent);
        color: var(--accent);
        background-color: var(--bg-card);
    }

    /* Specifically disable hover background for the mobile toggle when it's already in the open state */
    #mobile-menu-button.is-open:hover {
        background-color: transparent !important;
        border-color: var(--border) !important;
    }
}

/* Force transparency on mobile unless actively being interacted with,
   and even then avoid persistent background */
@media (hover: none) {

    .control-btn:hover,
    .control-btn:focus,
    .control-btn:active {
        background-color: transparent !important;
        border-color: var(--border);
    }
}

#mobile-menu-button.is-open {
    background-color: transparent !important;
    border-color: var(--border) !important;
    box-shadow: none !important;
}

/* --- Chars & Icons default visibility --- */
.lang-char,
.theme-icon-sun,
.theme-icon-moon {
    fill: currentColor;
    color: inherit;
    transition: all 0.3s ease;
}

/* Specific for Hero (White text on dark/transparent) */
#navbar:not(.navbar-scrolled) .control-btn {
    color: white;
}

/* Active Highlight - Always Cyan, even on hover */
.lang-char.lang-active,
.theme-icon-sun.active,
.theme-icon-moon.active {
    fill: #06B6D4 !important;
    color: #06B6D4 !important;
    font-weight: 700;
}

/* Hero Overrides for Light Theme (White borders/icons, Cyan only for active lang) */
.light-theme #navbar:not(.navbar-scrolled) .control-btn {
    border-color: white !important;
}

.light-theme #navbar:not(.navbar-scrolled) .lang-char:not(.lang-active),
.light-theme #navbar:not(.navbar-scrolled) .theme-icon-sun,
.light-theme #navbar:not(.navbar-scrolled) .theme-icon-moon {
    fill: white !important;
    color: white !important;
}

/* Hover (Selected) state for Hero in Light Theme: Switch to Deep Gray against white BG */
.light-theme #navbar:not(.navbar-scrolled) .control-btn:hover .lang-char:not(.lang-active),
.light-theme #navbar:not(.navbar-scrolled) .control-btn:hover .theme-icon-sun,
.light-theme #navbar:not(.navbar-scrolled) .control-btn:hover .theme-icon-moon {
    fill: #4A5568 !important;
    color: #4A5568 !important;
}

/* Hero Overrides for Dark Mode (Default) */
:not(.light-theme) #navbar:not(.navbar-scrolled) .control-btn {
    border-color: white !important;
}

:not(.light-theme) #navbar:not(.navbar-scrolled) .control-btn:hover {
    border-color: #06B6D4 !important;
}

:not(.light-theme) #navbar:not(.navbar-scrolled) .lang-char:not(.lang-active),
:not(.light-theme) #navbar:not(.navbar-scrolled) .theme-icon-sun,
:not(.light-theme) #navbar:not(.navbar-scrolled) .theme-icon-moon {
    fill: white !important;
    color: white !important;
}

/* Inactive features in 'Selected' (Hovered) state: Switch to Deep Gray only in Light Theme */
.light-theme .control-btn:hover .lang-char:not(.lang-active),
.light-theme .control-btn:hover .theme-icon-sun:not(.active),
.light-theme .control-btn:hover .theme-icon-moon:not(.active) {
    fill: #4A5568 !important;
    color: #4A5568 !important;
}

/* Scrolled Navbar, Mobile Menu Open (in Light Theme only) or general Light Theme context */
.light-theme #navbar.navbar-scrolled .lang-char:not(.lang-active),
.light-theme #navbar.navbar-scrolled .theme-icon-sun:not(.active),
.light-theme #navbar.navbar-scrolled .theme-icon-moon:not(.active),
.light-theme #mobile-menu.is-open .lang-char:not(.lang-active),
.light-theme #mobile-menu.is-open .theme-icon-sun:not(.active),
.light-theme #mobile-menu.is-open .theme-icon-moon:not(.active),
.light-theme .lang-char:not(.lang-active),
.light-theme .theme-icon-sun:not(.active),
.light-theme .theme-icon-moon:not(.active) {
    fill: #4A5568 !important;
    color: #4A5568 !important;
}

/* --- Theme Switcher Animation (Umami style) --- */
.theme-icon-container {
    position: relative;
    width: 1.25rem;
    height: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-icon-sun,
.theme-icon-moon {
    position: absolute;
    width: 100%;
    height: 100%;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: center;
}

/* Animation States */
.theme-icon-sun {
    opacity: 0;
    transform: rotate(-90deg) scale(0);
}

.theme-icon-moon {
    opacity: 0;
    transform: rotate(90deg) scale(0);
}

.theme-icon-sun.active {
    opacity: 1;
    transform: rotate(0) scale(1);
    color: #06B6D4 !important;
}

.theme-icon-moon.active {
    opacity: 1;
    transform: rotate(0) scale(1);
    color: #06B6D4 !important;
}

/* --- Main Logo --- */
.main-logo {
    width: 2.5rem;
    height: 2.5rem;
    background-color: var(--accent);
    -webkit-mask-image: url('../images/logo.svg');
    mask-image: url('../images/logo.svg');
    -webkit-mask-size: contain;
    mask-size: contain;
    -webkit-mask-position: center;
    mask-position: center;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    transition: background-color 0.3s ease;
}

/* --- Mobile Menu --- */
#mobile-menu.is-open {
    opacity: 1;
    pointer-events: auto;
}

.mobile-menu-controls {
    display: flex;
    gap: 2rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    width: 60%;
    justify-content: center;
}

.mobile-menu-controls .control-btn {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 1rem;
}

.mobile-menu-controls .control-btn svg {
    width: 1.5rem;
    height: 1.5rem;
}

.hamburger-line {
    transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19), opacity 0.2s ease;
    transform-origin: center;
}

#mobile-menu-button.is-open .line-top {
    transform: translateY(6px) rotate(45deg);
}

#mobile-menu-button.is-open .line-middle {
    opacity: 0;
}

#mobile-menu-button.is-open .line-bottom {
    transform: translateY(-6px) rotate(-45deg);
}

/* --- Cookie Banner --- */
#cookie-banner {
    background-color: var(--bg-glass);
    backdrop-filter: blur(16px);
    border-top: 1px solid var(--border);
    transform: translateY(100%);
    transition: transform 0.5s ease-in-out;
}

#cookie-banner.is-visible {
    transform: translateY(0);
}


@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}


@layer base {

    h1,
    h2,
    h3,
    h4,
    h5,
    h6 {
        color: var(--text-heading);
    }
}

/* Custom Components & Utilities */
.prose-invert blockquote,
blockquote {
    border-left: 4px solid var(--accent);
    padding: 1.25rem 2rem;
    font-style: italic;
    color: var(--text-body);
    background: var(--bg-card);
    border-radius: 0 1rem 1rem 0;
    margin: 2rem 0;
    line-height: 1.8;
}

/* Quill Editor Content Styles */
.ql-editor {
    padding: 0;
}

.ql-align-center {
    text-align: center;
}

.ql-align-right {
    text-align: right;
}

.ql-align-justify {
    text-align: justify;
}

.ql-size-small {
    font-size: 0.875rem;
}

.ql-size-large {
    font-size: 1.5rem;
}

.ql-size-huge {
    font-size: 2.25rem;
}

.ql-editor img {
    max-width: 100%;
    height: auto;
    border-radius: 1rem;
    margin: 1.5rem 0;
}

.ql-editor h1,
.ql-editor h2,
.ql-editor h3 {
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.ql-editor p {
    margin-bottom: 1.25rem;
}

.bg-glass {
    background-color: var(--bg-glass);
}

/* --- Skeleton Loading --- */
.skeleton {
    position: relative;
    overflow: hidden;
    background-color: var(--border);
    border-radius: 0.5rem;
}

.skeleton::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
    background-image: linear-gradient(90deg,
            rgba(255, 255, 255, 0) 0,
            rgba(255, 255, 255, 0.05) 20%,
            rgba(255, 255, 255, 0.1) 60%,
            rgba(255, 255, 255, 0));
    animation: shimmer 1.5s infinite;
}

.light-theme .skeleton::after {
    background-image: linear-gradient(90deg,
            rgba(255, 255, 255, 0) 0,
            rgba(0, 0, 0, 0.02) 20%,
            rgba(0, 0, 0, 0.05) 60%,
            rgba(255, 255, 255, 0));
}

@keyframes shimmer {
    100% {
        transform: translateX(100%);
    }
}

.skeleton-text {
    height: 1rem;
    width: 100%;
}

.skeleton-title {
    height: 2rem;
    width: 60%;
}

.skeleton-card {
    height: 300px;
    width: 100%;
}

.skeleton-circle {
    border-radius: 50%;
}