/* ========================================
   MAIN STYLESHEET - CUỘC THI TRỰC TUYẾN
   Dark Navy Blue Theme
   ======================================== */

/* ===== Root Variables ===== */
:root {
    --navy: #0B2063;
    --navy-dark: #071540;
    --navy-mid: #102878;
    --accent: #FFC107;
    --accent-hover: #FFB300;
    --white: #FFFFFF;
    --light-bg: #F0F4FE;
    --text-dark: #1a1a2e;
    --text-muted: #6b7a9a;
    --border: #e2e8f0;
    --shadow: 0 8px 32px rgba(11, 32, 99, 0.12);
    --shadow-lg: 0 16px 48px rgba(11, 32, 99, 0.18);
    --radius: 16px;
    --transition: all 0.3s ease;
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body.page-body {
    font-family: Arial, 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-dark);
    background: var(--white);
    line-height: 1.65;
    overflow-x: hidden;
}
a { color: var(--navy); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent); }
img { max-width: 100%; display: block; }

/* ===== NAVBAR ===== */
.site-header {
    background-color: var(--navy);
    box-shadow: 0 2px 16px rgba(11,32,99,0.3);
    z-index: 1050;
}
.site-header .navbar {
    background: transparent !important;
    padding: 0.6rem 0;
}
.site-header .navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0;
}
.logo-img {
    width: 48px;
    height: 48px;
    object-fit: contain;
    flex-shrink: 0;
}
.brand-text { display: flex; flex-direction: column; }
.brand-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--white);
    line-height: 1.2;
    letter-spacing: 0.5px;
}
.brand-subtitle {
    font-size: 0.72rem;
    font-weight: 500;
    color: rgba(255,255,255,0.85);
    line-height: 1.2;
    letter-spacing: 0.3px;
}
.site-header .navbar-nav { gap: 0; }
.site-header .nav-link {
    color: rgba(255,255,255,0.92) !important;
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.55rem 1rem !important;
    position: relative;
    transition: var(--transition);
}
.site-header .nav-link::after {
    content: '';
    position: absolute;
    bottom: 0; left: 1rem; right: 1rem;
    height: 2px;
    background: var(--accent);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}
.site-header .nav-link:hover,
.site-header .nav-link.active { color: var(--white) !important; }
.site-header .nav-link:hover::after,
.site-header .nav-link.active::after { transform: scaleX(1); }
.nav-auth-btns {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: 1rem;
}
.nav-auth-btns .btn-outline-light {
    border: 1.5px solid rgba(255,255,255,0.7);
    color: var(--white) !important;
    background: transparent;
    padding: 0.4rem 1rem;
    font-size: 0.875rem;
    border-radius: 6px;
    transition: var(--transition);
}
.nav-auth-btns .btn-outline-light:hover {
    background: rgba(255,255,255,0.15);
}
.nav-auth-btns .btn-warning {
    background: var(--accent);
    color: var(--text-dark) !important;
    border: none;
    padding: 0.4rem 1.1rem;
    font-size: 0.875rem;
    border-radius: 6px;
    font-weight: 700;
    transition: var(--transition);
}
.nav-auth-btns .btn-warning:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}
.site-header .navbar-toggler {
    border-color: rgba(255,255,255,0.4) !important;
}
.site-header .navbar-toggler-icon {
    filter: invert(1);
}

/* ===== HERO SECTION ===== */
.hero-section {
    position: relative;
    background:
        linear-gradient(110deg, rgba(7,21,64,0.90) 0%, rgba(11,32,99,0.78) 42%, rgba(16,40,120,0.52) 100%),
        url('../img/toanhahanhchinh4.jpg') center 60% / cover no-repeat;
    min-height: 580px;
    display: flex;
    align-items: center;
    overflow: hidden;
    padding: 60px 0 80px;
}
.hero-section::after {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 24%, rgba(79,195,247,0.14) 0%, transparent 42%),
        linear-gradient(180deg, rgba(7,21,64,0.08) 0%, rgba(7,21,64,0.58) 100%);
    pointer-events: none;
}
.hero-dots-pattern {
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(79,195,247,0.08) 1px, transparent 1px);
    background-size: 36px 36px;
    pointer-events: none;
    opacity: 0.65;
}
.hero-content {
    position: relative;
    z-index: 3;
    padding-right: 1rem;
}
.hero-title {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--white);
    line-height: 1.25;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 12px rgba(0,0,0,0.3);
}
.hero-highlight {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--accent);
    line-height: 1.2;
    margin-bottom: 1.25rem;
    text-shadow: 0 2px 12px rgba(0,0,0,0.25);
}
.hero-desc {
    font-size: 1rem;
    color: rgba(255,255,255,0.88);
    margin-bottom: 2rem;
    line-height: 1.7;
}
.hero-btns { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-btns .btn-warning {
    background: var(--accent);
    color: var(--text-dark);
    border: none;
    font-weight: 700;
    padding: 0.75rem 1.6rem;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}
.hero-btns .btn-warning:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255,193,7,0.4);
}
.hero-btns .btn-outline-light {
    border: 2px solid rgba(255,255,255,0.75);
    color: var(--white);
    background: transparent;
    padding: 0.75rem 1.6rem;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
}
.hero-btns .btn-outline-light:hover {
    background: rgba(255,255,255,0.12);
}

/* Hero right visual */
.hero-right {
    position: relative;
    height: 460px;
    z-index: 3;
}
.shield-wrap {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-55%, -55%);
    width: 280px;
    height: 300px;
    z-index: 2;
}
.shield-glow-ring {
    position: absolute;
    inset: -30px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(79,195,247,0.22) 0%, transparent 70%);
    animation: glow-pulse 3s ease-in-out infinite;
}
@keyframes glow-pulse {
    0%, 100% { opacity: 0.7; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.08); }
}
.shield-svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 0 18px rgba(79,195,247,0.5));
    animation: float 4s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}
.hero-building {
    position: absolute;
    bottom: 0;
    right: 0;
    /* width: 340px;
    height: 240px;
    object-fit: cover; */
    object-position: center bottom;
    opacity: 0.85;
    z-index: 1;
}

@media (max-width: 991.98px) {
    .hero-section {
        background:
            linear-gradient(120deg, rgba(7,21,64,0.92) 0%, rgba(11,32,99,0.80) 48%, rgba(16,40,120,0.60) 100%),
            url('../img/toanhahanhchinh4.jpg') center center / cover no-repeat;
    }
}

@media (max-width: 767.98px) {
    .hero-section {
        min-height: 500px;
        background:
            linear-gradient(180deg, rgba(7,21,64,0.88) 0%, rgba(11,32,99,0.78) 52%, rgba(16,40,120,0.70) 100%),
            url('../img/toanhahanhchinh4.jpg') 58% center / cover no-repeat;
    }
    .hero-section::after {
        background:
            radial-gradient(circle at 50% 14%, rgba(79,195,247,0.12) 0%, transparent 46%),
            linear-gradient(180deg, rgba(7,21,64,0.18) 0%, rgba(7,21,64,0.64) 100%);
    }
}

/* ===== STATS CARD SECTION ===== */
.stats-card-section {
    background: var(--white);
    position: relative;
    z-index: 10;
}
.stats-main-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 28px 36px;
    gap: 0;
    transform: translateY(-30px);
}
.stats-col {
    flex: 1;
    padding: 0 24px;
    text-align: center;
}
.stats-col-countdown { flex: 2; text-align: left; }
.stats-col-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.stats-col-countdown .stats-col-label { justify-content: flex-start; }
.stats-col-count .stats-col-label,
.stats-col-rank .stats-col-label { justify-content: center; }
.countdown-row {
    display: flex;
    gap: 20px;
    align-items: flex-end;
}
.cd-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}
.cd-num {
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--navy);
    line-height: 1;
    font-variant-numeric: tabular-nums;
}
.cd-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.8px;
}
.stats-divider {
    width: 1px;
    height: 80px;
    background: var(--border);
    flex-shrink: 0;
}
.stats-big-number {
    font-size: 2.6rem;
    font-weight: 700;
    color: var(--navy);
    line-height: 1;
    margin: 4px 0;
}
.stats-sub-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.8px;
    text-transform: uppercase;
}
.rank-trophy { margin: 6px 0; }
.rank-link {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--navy);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: var(--transition);
    border-bottom: 1.5px solid transparent;
}
.rank-link:hover {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

/* ===== SECTION COMMON ===== */
.section-title-blue {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--navy);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 10px;
}
.title-underline {
    width: 56px;
    height: 4px;
    background: var(--accent);
    margin: 0 auto;
    border-radius: 2px;
}

/* ===== WHY JOIN SECTION ===== */
.why-section { background: var(--white); }
.why-card {
    padding: 32px 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    height: 100%;
    transition: var(--transition);
    background: var(--white);
}
.why-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow);
}
.why-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 18px;
    font-size: 1.8rem;
}
.why-icon-blue   { background: #E8F0FF; color: #1D4ED8; }
.why-icon-green  { background: #E6F9F0; color: #059669; }
.why-icon-orange { background: #FFF4E5; color: #EA6C00; }
.why-icon-purple { background: #F5EEFF; color: #7C3AED; }
.why-title {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--navy);
    text-transform: uppercase;
    margin-bottom: 10px;
    letter-spacing: 0.3px;
}
.why-desc {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
    line-height: 1.65;
}

/* ===== STEPS SECTION ===== */
.steps-section { background: var(--light-bg); }
.steps-row { position: relative; }
.steps-row::before {
    content: '';
    position: absolute;
    top: 60px;
    left: calc(12.5% + 36px);
    right: calc(12.5% + 36px);
    height: 2px;
    background: repeating-linear-gradient(
        to right,
        #b0bec5 0,
        #b0bec5 8px,
        transparent 8px,
        transparent 18px
    );
    z-index: 0;
}
.step-col { position: relative; z-index: 1; }
.step-card { padding: 28px 16px 24px; }
.step-circle {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 10px;
    font-size: 1.7rem;
    color: var(--white);
    position: relative;
    z-index: 2;
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}
.step-blue   { background: linear-gradient(135deg, #1D4ED8, #3B82F6); }
.step-green  { background: linear-gradient(135deg, #059669, #34D399); }
.step-orange { background: linear-gradient(135deg, #EA6C00, #F59E0B); }
.step-purple { background: linear-gradient(135deg, #7C3AED, #A78BFA); }
.step-num {
    width: 24px;
    height: 24px;
    background: var(--navy);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    margin: 0 auto 12px;
}
.step-title {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--navy);
    text-transform: uppercase;
    margin-bottom: 8px;
    letter-spacing: 0.2px;
}
.step-desc {
    font-size: 0.825rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin: 0;
}

/* ===== SECURITY SECTION ===== */
.security-section {
    background: var(--navy);
    color: var(--white);
    position: relative;
    overflow: hidden;
}
.security-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(79,195,247,0.07) 1px, transparent 1px);
    background-size: 30px 30px;
    pointer-events: none;
}
.security-img {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
    filter: drop-shadow(0 8px 24px rgba(0,0,0,0.3));
}
.security-title {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
    line-height: 1.3;
}
.security-desc {
    color: rgba(255,255,255,0.82);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}
.security-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.security-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: rgba(255,255,255,0.92);
    font-weight: 500;
    font-size: 0.95rem;
}
.security-list li i {
    color: var(--accent);
    font-size: 1.1rem;
    flex-shrink: 0;
}

/* ===== FOOTER ===== */
.site-footer {
    background: var(--navy-dark);
    color: rgba(255,255,255,0.85);
    padding: 48px 0 0;
}
.footer-row { padding-bottom: 40px; }
.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}
.footer-logo {
    width: 44px;
    height: 44px;
    object-fit: contain;
    flex-shrink: 0;
}
.footer-brand-name {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--white);
    line-height: 1.3;
    letter-spacing: 0.3px;
}
.footer-addr,
.footer-phone {
    font-size: 0.83rem;
    color: rgba(255,255,255,0.72);
    line-height: 1.65;
    margin-bottom: 6px;
}
.footer-col-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--white);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    margin-bottom: 16px;
}
.footer-links-grid {
    display: flex;
    gap: 24px;
}
.footer-links-grid div {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.footer-links-grid a {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.72);
    transition: var(--transition);
}
.footer-links-grid a:hover { color: var(--accent); }
.social-icons {
    display: flex;
    gap: 12px;
    margin-top: 4px;
}
.social-icon {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--white);
    transition: var(--transition);
}
.social-icon:hover { transform: translateY(-3px); color: var(--white); }
.si-fb { background: #1877F2; }
.si-gg { background: #EA4335; }
.si-yt { background: #FF0000; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 18px 0;
    text-align: center;
}
.footer-bottom p {
    font-size: 0.82rem;
    color: rgba(255,255,255,0.55);
    margin: 0;
}

/* ===== MODALS ===== */
.modal-header-blue { background-color: var(--navy); }
.modal-content { border-radius: var(--radius); overflow: hidden; border: none; }
.modal-body .form-control:focus {
    border-color: var(--navy);
    box-shadow: 0 0 0 0.2rem rgba(11,32,99,0.15);
}
.modal-body .btn-warning {
    background: var(--accent);
    color: var(--text-dark);
    border: none;
    font-weight: 700;
    padding: 0.65rem 1.5rem;
    border-radius: 8px;
    transition: var(--transition);
}
.modal-body .btn-warning:hover { background: var(--accent-hover); }
.modal-body a { color: var(--navy); }
.modal-body a:hover { color: var(--accent); }