/* base.css - part of style.css split */

/*
 * Academic Website - Science Theme
 * โหลด theme.css ก่อน (ใน layout) แล้วค่อยโหลด style.css
 * ธีมสีเดียวจาก theme.css
 */

/* ================================
   Reset & Base Styles
   ================================ */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    overflow-x: hidden;
    font-family: var(--font-primary);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-gray-900);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

#main-content {
    flex: 1;
    scroll-margin-top: calc(var(--header-height, 80px) + var(--top-bar-height, 40px) + 0.5rem);
}

/* Skip link: hidden until focused (accessibility) */
.skip-link {
    position: absolute;
    left: -9999px;
    top: var(--spacing-4);
    z-index: 10000;
    padding: var(--spacing-3) var(--spacing-4);
    background: var(--color-primary);
    color: var(--color-dark);
    font-weight: 600;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transition: left var(--transition);
}
.skip-link:focus {
    left: var(--spacing-4);
    outline: 2px solid var(--color-dark);
    outline-offset: 2px;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

ul,
ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Touch: reduce double-tap zoom delay; intentional tap highlight (Safe Areas / Touch per web.mdc) */
a,
button,
.btn,
[role="button"] {
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(234, 179, 8, 0.25);
}

/* ================================
   Typography
   ================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-primary);
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-dark);
}

h1 {
    font-size: var(--text-5xl);
}

h2 {
    font-size: var(--text-4xl);
}

h3 {
    font-size: var(--text-3xl);
}

h4 {
    font-size: var(--text-2xl);
}

h5 {
    font-size: var(--text-xl);
}

h6 {
    font-size: var(--text-lg);
}

p {
    margin-bottom: var(--spacing-4);
}

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

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

.text-muted {
    color: var(--color-gray-600);
}

/* ================================
   Layout Components
   ================================ */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

.section {
    padding: var(--spacing-20) 0;
}

.section-dark {
    background-color: var(--color-dark);
    color: var(--color-white);
}

.section-light {
    background-color: var(--color-gray-100);
}

.section.section-light {
    padding: var(--spacing-8) 0;
}

.section-primary {
    background-color: var(--color-primary);
    color: var(--color-dark);
}

/* New Background Utilities */
.section-blue-light {
    background-color: #f0f9ff;
    /* Pale Blue */
    color: var(--color-dark);
}

.section-cream {
    background-color: #fffbeb;
    /* Warm Cream */
    color: var(--color-dark);
}

.news-section.section-cream {
    padding: var(--spacing-6) 0;
    margin: 0;
}

.section-white-pattern {
    background-color: #ffffff;
    background-image: radial-gradient(#e5e7eb 1px, transparent 1px);
    background-size: 20px 20px;
}

.section-dark-blue {
    background-color: #1e3a5f;
    color: var(--color-white);
}

.section-slate-gradient {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

/* ================================
   Top Bar (Audience Links)
   ================================ */
.top-bar {
    background-color: var(--color-dark);
    height: var(--top-bar-height);
    display: flex;
    align-items: center;
    padding-top: env(safe-area-inset-top);
}

.top-bar .container {
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.top-bar__links {
    display: flex;
    gap: var(--spacing-6);
}

.top-bar__link {
    color: var(--color-gray-400);
    font-size: var(--text-sm);
    transition: color var(--transition);
}

.top-bar__link:hover {
    color: var(--color-primary);
}

/* ================================
   Header & Navigation
   ================================ */
.header {
    background-color: var(--color-white);
    height: var(--header-height);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    padding-top: env(safe-area-inset-top);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.logo__icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo__icon svg {
    width: 28px;
    height: 28px;
    fill: var(--color-dark);
}

.logo__text {
    font-family: var(--font-serif);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--color-dark);
}

.logo__text span {
    display: block;
    font-size: var(--text-xs);
    font-weight: 400;
    color: var(--color-gray-600);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* Main Navigation */
.nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-8);
}

.nav__list {
    display: flex;
    gap: var(--spacing-6);
}

.nav__link {
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--color-gray-700);
    padding: var(--spacing-2) 0;
    position: relative;
    transition: color var(--transition);
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background-color: var(--color-primary);
    transition: width var(--transition);
}

.nav__link:hover,
.nav__link.active {
    color: var(--color-dark);
}

.nav__link:hover::after,
.nav__link.active::after {
    width: 100%;
}

.nav__search {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    transition: background-color var(--transition);
}

.nav__search:hover {
    background-color: var(--color-gray-100);
}

.nav__search svg {
    width: 20px;
    height: 20px;
    stroke: var(--color-gray-700);
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-dark);
    transition: all var(--transition);
}

/* Focus visible (accessibility) */
.menu-toggle:focus-visible,
.nav__search:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}
.btn:focus-visible,
.nav__link:focus-visible,
.footer__link:focus-visible,
.top-bar__link:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ================================
   Buttons
   ================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-6);
    font-size: var(--text-base);
    font-weight: 600;
    border-radius: var(--radius);
    transition: all var(--transition);
    cursor: pointer;
    min-height: 44px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #1a1a1a;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: var(--color-dark);
    color: var(--color-white);
}

.btn-secondary:hover {
    background-color: var(--color-dark-light);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--color-primary);
    color: var(--color-dark);
}

.btn-outline:hover {
    background-color: var(--color-primary);
}

.btn-lg {
    padding: var(--spacing-4) var(--spacing-8);
    font-size: var(--text-lg);
}

/* ================================
   Hero Section
   ================================ */
.hero {
    min-height: 600px;
    background: linear-gradient(135deg, var(--color-dark) 0%, var(--color-gray-900) 100%);
    color: var(--color-white);
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
    opacity: 0.9;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero__content {
    max-width: 600px;
}

.hero__subtitle {
    font-size: var(--text-sm);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-4);
}

.hero__title {
    font-size: var(--text-6xl);
    color: var(--color-white);
    margin-bottom: var(--spacing-6);
    line-height: 1.1;
}

.hero__description {
    font-size: var(--text-lg);
    color: var(--color-gray-300);
    margin-bottom: var(--spacing-8);
    line-height: 1.7;
}

.hero__actions {
    display: flex;
    gap: var(--spacing-4);
    flex-wrap: wrap;
}

/* ================================
   Cards
   ================================ */
.card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all var(--transition);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card__image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card__content {
    padding: var(--spacing-6);
}

.card__category {
    display: inline-block;
    font-size: var(--text-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--primary);
    margin-bottom: var(--spacing-2);
}

.card__title {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-3);
}

.card__title a:hover {
    color: var(--primary);
}

.card__excerpt {
    color: var(--color-gray-600);
    font-size: var(--text-sm);
    margin-bottom: var(--spacing-4);
}

.card__meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    font-size: var(--text-sm);
    color: var(--color-gray-500);
}

/* Profile Card */
.profile-card {
    text-align: center;
    padding: var(--spacing-8);
}

.profile-card__image {
    width: 120px;
    height: 120px;
    border-radius: var(--radius-full);
    object-fit: cover;
    margin: 0 auto var(--spacing-4);
    border: 4px solid var(--color-primary);
}

.profile-card__name {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-1);
}

.profile-card__role {
    color: var(--color-gray-600);
    font-size: var(--text-sm);
}

/* ================================
   Grid Layouts
   ================================ */
.grid {
    display: grid;
    gap: var(--spacing-6);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.grid-6 {
    grid-template-columns: repeat(6, 1fr);
}

/* ================================
   News Section
   ================================ */
.news-section {
    padding: var(--spacing-8) 0;
    margin: 0;
}

.news-section__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-4);
    flex-wrap: wrap;
    gap: var(--spacing-3);
}

.news-section__title {
    font-size: var(--text-3xl);
}

.news-section__link {
    color: var(--primary);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.news-section__link:hover {
    text-decoration: underline;
}

/* Featured News - 3 columns x 2 rows = 6 items */
.featured-news {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: auto auto;
    /* 2 rows x 3 columns = 6 items total */
    gap: var(--spacing-4);
    grid-auto-flow: row;
    align-items: start;
}

/* All cards take equal space - 1 column x 1 row each */
.featured-news>article {
    grid-column: span 1;
    grid-row: span 1;
}

/* All cards have consistent styling */
.featured-news .card {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.featured-news .card__image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.featured-news .card__content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    padding: var(--spacing-3);
    background: #fff;
    transition: background 0.3s ease;
}

/* Background colors for different news categories */
.featured-news .card__content--research_grant {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    /* Amber/Yellow gradient for research grants */
}

.featured-news .card__content--student_activity {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    /* Blue gradient for student activities */
}

.featured-news .card__content--general {
    background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
    /* Gray gradient for general news */
}

.featured-news .card__category {
    margin-bottom: var(--spacing-1);
    font-size: var(--text-xs);
}

.featured-news .card__title {
    font-size: var(--text-base);
    margin-bottom: var(--spacing-1);
    line-height: 1.3;
}

.featured-news .card__excerpt {
    margin-bottom: var(--spacing-1);
    font-size: var(--text-xs);
    color: var(--color-gray-600);
    line-height: 1.4;
}

.featured-news .card__meta {
    margin-top: auto;
    font-size: var(--text-xs);
    color: var(--color-gray-500);
    padding-top: var(--spacing-1);
}

/* Responsive News Grid */
@media (max-width: 1024px) {
    .featured-news {
        grid-template-columns: repeat(2, 1fr);
        grid-template-rows: auto auto auto;
        /* 3 rows x 2 columns = 6 items on tablet */
        gap: var(--spacing-3);
    }

    .featured-news .card__image {
        height: 180px;
    }
}

@media (max-width: 640px) {
    .top-bar {
        display: none;
    }
    .logo__text {
        min-width: 0;
        overflow: hidden;
        text-overflow: ellipsis;
        font-size: var(--text-base);
    }
    .logo__text span {
        font-size: 0.65rem;
    }
    .news-section__header {
        flex-direction: column;
        align-items: flex-start;
    }
    .featured-news {
        grid-template-columns: 1fr;
        grid-template-rows: auto;
        /* Single column, all items stack */
        gap: var(--spacing-3);
    }

    .featured-news .card__image {
        height: 200px;
    }
}

/* ================================
   Section Headers
   ================================ */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-4);
}

.section-header__subtitle {
    display: inline-block;
    color: var(--primary);
    font-size: var(--text-lg);
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-2);
    padding: 0.5rem 1.25rem;
    background: linear-gradient(135deg, rgba(30, 58, 95, 0.12) 0%, rgba(45, 90, 135, 0.08) 100%);
    border-radius: 50px;
    border: 1px solid rgba(30, 58, 95, 0.25);
}

.section-header__title {
    margin-bottom: var(--spacing-2);
}

.section-header__description {
    color: var(--color-gray-600);
    font-size: var(--text-lg);
}

/* ================================
   Feature Sections (Academics, Research, etc.)
   ================================ */
.feature-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: center;
}

.feature-section--reverse {
    direction: rtl;
}

.feature-section--reverse>* {
    direction: ltr;
}

.feature-section__content {
    max-width: 500px;
}

.feature-section__subtitle {
    color: var(--color-primary-dark);
    font-size: var(--text-sm);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    margin-bottom: var(--spacing-4);
}

.feature-section__title {
    margin-bottom: var(--spacing-4);
}

.feature-section__description {
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-6);
}

.feature-section__image {
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.feature-section__image img {
    width: 100%;
    height: 400px;
    object-fit: cover;
}

/* Feature List */
.feature-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-6);
}

.feature-list__item {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.feature-list__icon {
    width: 24px;
    height: 24px;
    background-color: var(--color-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.feature-list__icon svg {
    width: 14px;
    height: 14px;
    stroke: var(--color-dark);
}

/* ================================
   Stats Section
   ================================ */
.stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-8);
    text-align: center;
}

.stat {
    padding: var(--spacing-8);
}

.stat__number {
    font-family: var(--font-serif);
    font-size: var(--text-5xl);
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: var(--spacing-2);
}

.stat__label {
    font-size: var(--text-sm);
    color: var(--color-gray-600);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* ================================
   CTA Section
   ================================ */
.cta-section {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    padding: var(--spacing-20) 0;
    text-align: center;
}

.cta-section__title {
    font-size: var(--text-4xl);
    margin-bottom: var(--spacing-4);
}

.cta-section__description {
    font-size: var(--text-lg);
    margin-bottom: var(--spacing-8);
    opacity: 0.9;
}

/* ================================
   Footer
   ================================ */
.footer {
    background-color: var(--color-dark);
    color: var(--color-gray-400);
    padding-top: var(--spacing-16);
    padding-bottom: env(safe-area-inset-bottom);
}

.footer__main {
    display: grid;
    grid-template-columns: 2fr repeat(4, 1fr);
    gap: var(--spacing-10);
    padding-bottom: var(--spacing-12);
    border-bottom: 1px solid var(--color-gray-800);
}

.footer__brand {
    padding-right: var(--spacing-8);
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    margin-bottom: var(--spacing-4);
}

.footer__logo-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: var(--radius-md);
}

.footer__logo-text {
    font-family: var(--font-serif);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--color-white);
}

.footer__description {
    font-size: var(--text-sm);
    line-height: 1.7;
    margin-bottom: var(--spacing-6);
}

.footer__social {
    display: flex;
    gap: var(--spacing-3);
}

.footer__social-link {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background-color: var(--color-gray-800);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
}

.footer__social-link:hover {
    background-color: var(--color-primary);
    color: var(--color-dark);
}

.footer__social-link svg {
    width: 18px;
    height: 18px;
}

.footer__column h4 {
    color: var(--color-white);
    font-size: var(--text-base);
    font-family: var(--font-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-4);
}

.footer__links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.footer__link {
    font-size: var(--text-sm);
    transition: color var(--transition);
}

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

.footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-6) 0;
    font-size: var(--text-sm);
}

.footer__legal {
    display: flex;
    gap: var(--spacing-6);
}

/* ================================