/* =========================
   EYEBROW / SMALL LABEL
========================= */
.eyebrow {
    margin-bottom: 12px;
    color: rgba(255,255,255,0.58);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

/* =========================
   TEXT LINK
========================= */
.text-link {
    color: var(--text);
    font-weight: 500;
    border-bottom: 1px solid transparent;
    text-decoration: none;
    transition: border-color var(--transition), color var(--transition), opacity var(--transition);
}

.text-link:hover {
    border-color: rgba(255,255,255,0.18);
    opacity: 0.9;
}

/* =========================
   BUTTON
========================= */
.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 20px;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,0.12);
    color: #fff;
    background: rgba(255,255,255,0.04);
    font-weight: 600;
    text-decoration: none;
    transition:
        transform var(--transition),
        background var(--transition),
        border-color var(--transition),
        box-shadow var(--transition),
        color var(--transition);
    backdrop-filter: blur(8px);
}

.button--primary {
    background: linear-gradient(
        135deg,
        rgba(79,209,197,0.22),
        rgba(124,131,253,0.20)
    );
    border: 1px solid rgba(255,255,255,0.10);
    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.05),
        0 10px 30px rgba(0,0,0,0.18);
}

.button--ghost {
    background: transparent;
}

.button:hover {
    transform: translateY(-2px);
    background: rgba(255,255,255,0.08);
    border-color: rgba(255,255,255,0.18);
}

.hero__actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 24px;
}

.hero__actions--left {
    justify-content: center;
}

/* =========================
   NAVBAR
========================= */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: linear-gradient(
        to bottom,
        rgba(5,7,11,0.82),
        rgba(5,7,11,0.28),
        transparent
    );
    backdrop-filter: blur(8px);
    transition:
        background var(--transition),
        backdrop-filter var(--transition),
        border-color var(--transition);
}

.site-header__inner {
    min-height: 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

/* dùng class này nếu JS add is-scrolled */
.site-header.is-scrolled,
.site-header.scrolled {
    background: rgba(5, 7, 11, 0.68);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.03);
}

/* =========================
   BRAND
========================= */
.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    letter-spacing: -0.02em;
    text-decoration: none;
}

.brand__dot,
.brand__mark {
    width: 10px;
    height: 10px;
    border-radius: 999px;
    background: linear-gradient(135deg, #4FD1C5, #7C83FD);
    box-shadow: 0 0 20px rgba(79, 209, 197, 0.35);
    flex: 0 0 auto;
}

.brand__text {
    color: rgba(255,255,255,0.88);
    font-weight: 700;
}

/* =========================
   NAV LINKS
========================= */
.site-nav {
    display: flex;
    align-items: center;
    gap: 28px;
}

.site-nav a {
    color: rgba(255,255,255,0.72);
    font-size: 15px;
    position: relative;
    text-decoration: none;
    transition: color var(--transition), opacity var(--transition);
}

.site-nav a.is-active,
.site-nav a:hover {
    color: #fff;
}

.site-nav a::after {
    content: "";
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--text);
    transition: width 0.3s ease;
}

.site-nav a:hover::after,
.site-nav a.is-active::after {
    width: 100%;
}

/* =========================
   MOBILE BUTTON
========================= */
.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border-radius: 999px;
    border: 1px solid var(--line);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 4px;
    background: rgba(255,255,255,0.02);
}

.menu-toggle span {
    width: 16px;
    height: 2px;
    background: var(--text);
    display: block;
}

/* =========================
   MOBILE MENU
========================= */
.mobile-menu {
    display: none;
    flex-direction: column;
    padding: 20px 16px;
    background: rgba(10, 15, 23, 0.96);
    border-top: 1px solid var(--line);
}

.mobile-menu a {
    padding: 12px 0;
    color: var(--text-secondary);
    text-decoration: none;
}

.mobile-menu a:hover,
.mobile-menu a.is-active {
    color: var(--text);
}

.mobile-menu.active {
    display: flex;
}

/* =========================
   POST CARD
========================= */
.post-card {
    position: relative;
    min-height: 100%;
    border-radius: 24px;
    border: 1px solid rgba(255,255,255,0.08);
    background: linear-gradient(
        180deg,
        rgba(255,255,255,0.03),
        rgba(255,255,255,0.02)
    );
    overflow: hidden;
    backdrop-filter: blur(6px);
    transition:
        transform var(--transition),
        border-color var(--transition),
        background var(--transition),
        box-shadow var(--transition);
}

.post-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at top left, rgba(79, 209, 197, 0.10), transparent 32%),
        radial-gradient(circle at bottom right, rgba(124, 131, 253, 0.10), transparent 34%);
    opacity: 0.65;
    pointer-events: none;
}

.post-card:hover {
    transform: translateY(-6px);
    border-color: rgba(255,255,255,0.14);
    background: rgba(255,255,255,0.06);
    box-shadow: 0 20px 60px rgba(0,0,0,0.32);
}

.post-card__link {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 100%;
    padding: 24px;
    text-decoration: none;
}

.post-card__top {
    margin-bottom: 24px;
}

.post-card__meta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    font-size: 13px;
    color: var(--muted);
    letter-spacing: 0.01em;
}

.post-card__category {
    color: var(--text-secondary);
    font-weight: 600;
}

.post-card__dot {
    opacity: 0.6;
}

.post-card__date {
    color: var(--muted);
}

.post-card__body {
    flex: 1;
}

.post-card__title {
    margin: 0 0 14px;
    color: #fff;
    font-size: clamp(22px, 2vw, 28px);
    line-height: 1.08;
    letter-spacing: -0.035em;
    font-weight: 700;
}

.post-card__excerpt {
    margin: 0;
    color: rgba(255,255,255,0.72);
    font-size: 15px;
    line-height: 1.7;
    max-width: 42ch;
}

.post-card__bottom {
    margin-top: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text);
}

.post-card__read {
    font-size: 14px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.post-card__arrow {
    font-size: 18px;
    opacity: 0.85;
    transition: transform var(--transition), opacity var(--transition);
}

.post-card:hover .post-card__arrow {
    transform: translateX(4px);
    opacity: 1;
}

/* =========================
   FOOTER
========================= */

.site-footer {
    padding: 40px 0;
    border-top: 1px solid rgba(255,255,255,0.05);
    background: #05070B;
    position: relative;
    z-index: 1;
}

.site-footer__copy,
.site-footer__text {
    color: rgba(255,255,255,0.28);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.brand__logo {
    width: 32px;
    height: 32px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 auto;
}

.brand__logo svg {
    width: 100%;
    height: 100%;
    display: block;
}

.brand__text {
    color: rgba(255,255,255,0.88);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.brand:hover .brand__logo {
    transform: scale(1.04);
    transition: transform 0.2s ease;
}

.text-link {
    color: var(--text);
    font-weight: 600;
    opacity: 0.82;
    transition: opacity var(--transition), color var(--transition);
}

.text-link:hover {
    color: var(--primary);
    opacity: 1;
}

.button {
    min-height: 52px;
    padding: 0 22px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.04);
    color: var(--text);
    font-weight: 700;
    letter-spacing: -0.02em;
    backdrop-filter: blur(10px);
}

.button:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: var(--line-strong);
}

.button--primary {
    background: linear-gradient(135deg, rgba(125, 226, 209, 0.24), rgba(138, 146, 255, 0.2));
    box-shadow: 0 16px 44px rgba(0, 0, 0, 0.26);
}

.button--ghost {
    background: rgba(255, 255, 255, 0.02);
}

.hero__actions {
    justify-content: flex-start;
    margin-top: 28px;
}

.site-header {
    inset: 0 0 auto;
    z-index: 20;
    border-bottom: 1px solid transparent;
    background: linear-gradient(180deg, rgba(3, 5, 10, 0.84), rgba(3, 5, 10, 0.24), transparent);
    backdrop-filter: blur(10px);
}

.site-header.scrolled {
    background: rgba(5, 9, 16, 0.72);
    border-color: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(16px);
}

.site-header__inner {
    min-height: 84px;
    gap: 24px;
}

.brand {
    gap: 12px;
}

.brand__logo {
    width: 34px;
    height: 34px;
    transition: transform var(--transition);
}

.brand__logo svg {
    width: 100%;
    height: 100%;
}

.brand__text {
    color: rgba(255, 255, 255, 0.92);
    letter-spacing: -0.03em;
}

.site-nav a {
    color: var(--text-secondary);
    font-size: 0.96rem;
}

.site-nav a::after {
    bottom: -7px;
    width: 100%;
    transform: scaleX(0);
    transform-origin: left;
    background: linear-gradient(90deg, var(--primary), transparent);
}

.site-nav a:hover::after,
.site-nav a.is-active::after {
    width: 100%;
    transform: scaleX(1);
}

.menu-toggle {
    width: 46px;
    height: 46px;
    background: rgba(255, 255, 255, 0.03);
    cursor: pointer;
}

.menu-toggle span {
    width: 18px;
}

.mobile-menu {
    gap: 12px;
    padding: 16px 20px 20px;
    background: rgba(5, 9, 16, 0.94);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.mobile-menu a {
    padding: 8px 0;
}

.topic-list {
    justify-content: flex-start;
}

.topic-list--start {
    margin-bottom: 28px;
}

.topic-pill {
    min-height: 42px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-secondary);
}

.topic-pill:hover,
.topic-pill.is-active {
    background: rgba(125, 226, 209, 0.12);
    border-color: rgba(125, 226, 209, 0.26);
    color: var(--text);
}

.post-card {
    border-radius: var(--radius-md);
    border: 1px solid var(--line);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    backdrop-filter: blur(10px);
    box-shadow: 0 16px 56px rgba(0, 0, 0, 0.24);
}

.post-card::before {
    background:
        radial-gradient(circle at top left, rgba(125, 226, 209, 0.14), transparent 34%),
        radial-gradient(circle at bottom right, rgba(138, 146, 255, 0.12), transparent 34%);
    opacity: 0.9;
}

.post-card:hover {
    border-color: rgba(255, 255, 255, 0.18);
    box-shadow: 0 24px 72px rgba(0, 0, 0, 0.34);
}

.post-card__link {
    min-height: 100%;
    padding: 26px;
}

.post-card__top {
    margin-bottom: 26px;
}

.post-card__meta {
    font-size: 0.86rem;
    color: var(--text-muted);
}

.post-card__category {
    color: var(--primary);
    font-weight: 700;
}

.post-card__dot {
    font-size: 0;
}

.post-card__dot::before {
    content: "\2022";
    font-size: 0.86rem;
}

.post-card__title {
    margin-bottom: 14px;
    font-size: clamp(1.5rem, 2vw, 2rem);
}

.post-card__excerpt {
    max-width: 38ch;
}

.post-card__bottom {
    gap: 16px;
}

.post-card__read {
    color: var(--text);
    font-weight: 700;
}

.post-card__arrow {
    font-size: 0;
}

.post-card__arrow::before {
    content: "\2192";
    font-size: 1.2rem;
    display: inline-block;
    transition: transform var(--transition);
}

.post-card:hover .post-card__arrow::before {
    transform: translateX(5px);
}

.site-footer {
    padding: 28px 0 42px;
    background: rgba(4, 7, 13, 0.84);
}

.site-footer__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.site-footer__copy,
.site-footer__text {
    color: var(--text-muted);
}

.site-footer__copy {
    margin-bottom: 6px;
}

.site-footer__link {
    color: var(--text);
    font-weight: 700;
}

@media (max-width: 860px) {
    .site-nav {
        display: none;
    }

    .menu-toggle {
        display: inline-flex;
    }
}

@media (max-width: 680px) {
    .site-header__inner {
        min-height: 74px;
    }

    .post-card__link {
        padding: 22px;
    }

    .site-footer__inner {
        flex-direction: column;
        align-items: flex-start;
    }
}