:root {
    color-scheme: light;
    --primary-start: #00713f;
    --primary-end: #6a9f2e;
    --primary-dark: #00562f;
    --text-main: #1b2a1f;
    --text-muted: #49634f;
    --text-light: #f6fff6;
    --surface: #ffffff;
    --surface-alt: #f4f9f4;
    --page-bg: #eef6ee;
    --card-shadow: 0 12px 40px -30px rgba(0,0,0,0.25);
    --card-shadow-hover: 0 20px 40px -22px rgba(0,0,0,0.3);
    --overlay-soft: rgba(255,255,255,0.1);
    --border-soft: rgba(0,0,0,0.08);
}
[data-theme="dark"] {
    color-scheme: dark;
    --text-main: #e6f6e6;
    --text-muted: #b1d2b1;
    --text-light: #f3fff3;
    --surface: #17261d;
    --surface-alt: #1f3126;
    --page-bg: #0c1812;
    --card-shadow: 0 12px 40px -35px rgba(0,0,0,0.8);
    --card-shadow-hover: 0 20px 40px -26px rgba(0,0,0,0.85);
    --overlay-soft: rgba(255,255,255,0.05);
    --border-soft: rgba(255,255,255,0.08);
}
body {
    font-family: 'Prompt', sans-serif;
    color: var(--text-main);
    background: var(--page-bg);
    scroll-behavior: smooth;
    transition: background-color 0.35s ease, color 0.35s ease;
}

a{
    color: var(--text-main);
    text-decoration: none;
    transition: color 0.2s ease;
}

.bg-light {
    background: var(--surface-alt) !important;
    transition: background-color 0.35s ease, color 0.35s ease;
}
.card,
.form-control,
.form-select {
    background: var(--surface);
    border-color: var(--border-soft);
    color: var(--text-main);
    transition: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}
.form-control::placeholder {
    color: var(--text-muted);
}
.card-track {
    border: 0;
    border-radius: 1.25rem;
    background: linear-gradient(160deg, rgba(0,113,63,0.12), rgba(106,159,46,0.16));
    box-shadow: var(--card-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card-track:hover {
    transform: translateY(-8px);
    box-shadow: var(--card-shadow-hover);
}
.navbar {
    transition: background-color 0.3s ease, box-shadow 0.3s ease, color 0.3s ease;
}
.navbar.scrolled {
    background: #ffffffee;
    box-shadow: 0 10px 30px -20px rgba(0,0,0,0.45);
}

/* Navbar toggler (dark mode): prevent overly bright default Bootstrap icon/button */
[data-theme="dark"] .navbar .navbar-toggler {
    border-color: var(--border-soft);
    background: transparent;
}
[data-theme="dark"] .navbar .navbar-toggler:hover {
    background: var(--overlay-soft);
}
[data-theme="dark"] .navbar .navbar-toggler:focus {
    box-shadow: 0 0 0 0.15rem var(--border-soft);
}
[data-theme="dark"] .navbar .navbar-toggler-icon {
    /* Replace Bootstrap's data-URI (often too bright) with a mask that can use theme variables */
    background-image: none;
    background-color: var(--text-muted);
    -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3E%3Cpath stroke='black' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E");
    mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3E%3Cpath stroke='black' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E");
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    -webkit-mask-position: center;
    mask-position: center;
    -webkit-mask-size: 100% 100%;
    mask-size: 100% 100%;
}

@media (max-width: 991.98px) {
    body:not([data-theme="dark"]) .navbar.nav-open {
        background: var(--surface);
        box-shadow: 0 10px 30px -20px rgba(0,0,0,0.35);
    }
    body:not([data-theme="dark"]) .navbar.nav-open .navbar-collapse {
        background: var(--surface-alt);
        border: 1px solid var(--border-soft);
        border-radius: 0.9rem;
        margin-top: 0.75rem;
        padding: 0.75rem 1rem;
    }
    body:not([data-theme="dark"]) .navbar.nav-open .nav-link {
        color: var(--text-muted) !important;
    }
    body:not([data-theme="dark"]) .navbar.nav-open .nav-link.active,
    body:not([data-theme="dark"]) .navbar.nav-open .nav-link:hover {
        color: var(--primary-start) !important;
    }

    [data-theme="dark"] .navbar.nav-open {
        background: rgba(23,38,29,0.92);
        box-shadow: 0 15px 40px -30px rgba(0,0,0,0.85);
    }
    [data-theme="dark"] .navbar.nav-open .navbar-collapse {
        background: var(--surface-alt);
        border: 1px solid var(--border-soft);
        border-radius: 0.9rem;
        margin-top: 0.75rem;
        padding: 0.75rem 1rem;
    }
}
.nav-link {
    font-weight: 500;
    color: var(--text-muted);
    transition: color 0.2s ease;
}
.nav-link.active,
.nav-link:hover {
    color: var(--primary-start) !important;
}
body:not([data-theme="dark"]) .navbar .nav-link {
    color: #ffffff;
}
body:not([data-theme="dark"]) .navbar .nav-link.active,
body:not([data-theme="dark"]) .navbar .nav-link:hover {
    color: rgba(255,255,255,0.85) !important;
}
body:not([data-theme="dark"]) .navbar.scrolled .nav-link {
    color: var(--text-muted);
}
body:not([data-theme="dark"]) .navbar.scrolled .nav-link.active,
body:not([data-theme="dark"]) .navbar.scrolled .nav-link:hover {
    color: var(--primary-start) !important;
}
.hero {
    padding-top: 100px;
    padding-bottom: 30px;
    background: linear-gradient(135deg, rgba(0,113,63,0.92), rgba(106,159,46,0.92)), url('images/mekongict.png') center/cover no-repeat;
    color: var(--text-light);
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}
.hero-small {
    min-height: 80px;
    background: linear-gradient(135deg, rgba(0,113,63,0.92), rgba(106,159,46,0.92)), url('images/mekongict.png') center/cover no-repeat;
    color: var(--text-light);
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}
.hero::after {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at top right, rgba(255,255,255,0.15), transparent 55%);
}
.hero-content {
    position: relative;
    z-index: 1;
}

/* Breadcrumb (รองรับ light/dark mode ด้วยตัวแปรสี) */
.breadcrumb {
    margin: 0;
    padding: 0.55rem 1rem;
    background: none;
    box-shadow: 0 10px 30px -28px rgba(0,0,0,0.35);
    transition: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.breadcrumb-item + .breadcrumb-item::before {
    color: var(--text-muted);
    opacity: 0.85;
}

.breadcrumb a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.breadcrumb-item.active {
    color: var(--text-main);
    font-weight: 500;
}

/* ถ้า breadcrumb อยู่บน hero ให้คอนทราสต์ดีขึ้น */
.hero .breadcrumb,
.hero-small .breadcrumb {
    background: var(--overlay-soft);
    border-color: rgba(255,255,255,0.18);
    box-shadow: none;
}

.hero .breadcrumb a,
.hero-small .breadcrumb a,
.hero .breadcrumb-item.active,
.hero-small .breadcrumb-item.active,
.hero .breadcrumb-item + .breadcrumb-item::before,
.hero-small .breadcrumb-item + .breadcrumb-item::before {
    color: var(--text-light);
}

/* ปรับเพิ่มสำหรับโหมดมืด */
[data-theme="dark"] .breadcrumb {
    background: rgba(23, 38, 29, 0.65);
    box-shadow: 0 12px 40px -35px rgba(0,0,0,0.8);
}

[data-theme="dark"] .breadcrumb a:hover {
    color: var(--text-light);
}

.section-title {
    font-size: 2.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}
.highlight-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--overlay-soft);
    border-radius: 999px;
    padding: 0.5rem 1.25rem;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}
.timeline {
    position: relative;
    padding-left: 1.5rem;
}
.timeline::before {
    content: "";
    position: absolute;
    left: 9px;
    top: 8px;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-start), var(--primary-end));
}
.timeline-item {
    position: relative;
    padding-bottom: 1.5rem;
}
.timeline-item::before {
    content: "";
    position: absolute;
    left: -1.5rem;
    top: 0.35rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-end);
    border: 3px solid var(--surface);
    box-shadow: 0 0 0 3px rgba(0,113,63,0.15);
}
.objectives-list li {
    margin-bottom: 0.85rem;
    padding-left: 1.5rem;
    position: relative;
}
.objectives-list li::before {
    content: "✔";
    position: absolute;
    left: 0;
    top: 0.05rem;
    color: var(--primary-start);
    font-weight: 600;
}
.cta-section {
    background: linear-gradient(135deg, var(--primary-start), var(--primary-end));
    color: var(--text-light);
    border-radius: 1.75rem;
    padding: 3rem;
    position: relative;
    overflow: hidden;
    isolation: isolate;
}
.cta-section::after {
    content: "";
    position: absolute;
    inset: -40% -10%;
    background: radial-gradient(circle, rgba(255,255,255,0.18), transparent 50%);
    transform: rotate(25deg);
    z-index: -1;
}
.footer {
    background: #0f1f15;
    color: rgba(255,255,255,0.82);
    transition: background-color 0.35s ease, color 0.35s ease;
}
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}
@media (max-width: 992px) {
    .section-title {
        font-size: 2rem;
    }
    .hero {
        text-align: center;
    }
    .timeline::before {
        left: 7px;
    }
    .timeline-item::before {
        left: -1.65rem;
    }
}
@media (max-width: 576px) {
    .section-title {
        font-size: 1.75rem;
    }
    .cta-section {
        padding: 2rem 1.5rem;
    }
}
[data-theme="dark"] body {
    background: var(--page-bg);
    color: var(--text-main);
}
[data-theme="dark"] .navbar {
    background: rgba(13,24,18,0.35);
    box-shadow: none;
}
[data-theme="dark"] .navbar.scrolled {
    background: rgba(23,38,29,0.92);
    box-shadow: 0 15px 40px -30px rgba(0,0,0,0.85);
}
[data-theme="dark"] .nav-link.active,
[data-theme="dark"] .nav-link:hover {
    color: var(--text-light) !important;
}
[data-theme="dark"] .hero {
    background: linear-gradient(135deg, rgba(0,50,28,0.9), rgba(0,113,63,0.72)), url('images/mekongict.png') center/cover no-repeat;
}
[data-theme="dark"] .card-track {
    background: linear-gradient(160deg, rgba(0,113,63,0.22), rgba(106,159,46,0.14));
}
[data-theme="dark"] .timeline::before {
    background: linear-gradient(180deg, rgba(0,113,63,0.65), rgba(106,159,46,0.6));
}
[data-theme="dark"] .timeline-item::before {
    background: var(--primary-start);
    border-color: var(--surface);
    box-shadow: 0 0 0 3px rgba(0,113,63,0.35);
}
[data-theme="dark"] .footer {
    background: #050c08;
    color: rgba(255,255,255,0.7);
}