/* Reset nhẹ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg: #0f172a;
    --bg-soft: #111827;
    --primary: #38bdf8;
    --primary-soft: rgba(56,189,248,0.1);
    --text: #e5e7eb;
    --text-soft: #9ca3af;
    --card: #020617;
    --border: #1f2933;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-soft: 0 18px 45px rgba(15,23,42,0.6);
}
.form-group select {
    width: 100%;
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid #374151;
    background: #020617;
    color: #e5e7eb;
    font-size: 13px;
}
.download-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
}

.download-list a {
    flex: 1;
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
    background: radial-gradient(circle at top, #1e293b, #020617 55%);
    color: var(--text);
    min-height: 100vh;
    padding: 24px 16px 48px;
    display: flex;
    justify-content: center;
}

.page {
    width: 100%;
    max-width: 1040px;
}

/* HEADER */
header {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 32px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 14px;
}

.avatar {
    width: 54px;
    height: 54px;
    border-radius: 999px;
    border: 2px solid var(--primary);
    background: linear-gradient(135deg, #0ea5e9, #22c55e);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #0b1120;
    font-size: 24px;
    box-shadow: 0 10px 30px rgba(56,189,248,0.5);
}

.brand-text {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.brand-text h1 {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 0.03em;
}

.brand-text span {
    font-size: 13px;
    color: var(--text-soft);
}

/* NAV */
nav {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

nav a {
    font-size: 13px;
    padding: 8px 14px;
    border-radius: 999px;
    border: 1px solid rgba(148,163,184,0.35);
    text-decoration: none;
    color: var(--text-soft);
    backdrop-filter: blur(16px);
    background: linear-gradient(to right, rgba(15,23,42,0.9), rgba(15,23,42,0.7));
    transition: all 0.18s ease-out;
}

nav a:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-1px);
}

/* LAYOUT MAIN */
main {
    display: grid;
    grid-template-columns: minmax(0, 2.1fr) minmax(0, 1.2fr);
    gap: 24px;
}

@media (max-width: 860px) {
    main {
        grid-template-columns: 1fr;
    }
}

/* HERO */
.hero {
    background: radial-gradient(circle at top left, #1e293b, #020617 60%);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(148,163,184,0.3);
    box-shadow: var(--shadow-soft);
    padding: 22px 24px 24px;
    margin-bottom: 18px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    inset: -60%;
    background:
        radial-gradient(circle at 0 0, rgba(56,189,248,0.1), transparent 55%),
        radial-gradient(circle at 100% 0, rgba(34,197,94,0.12), transparent 55%);
    opacity: 0.7;
    pointer-events: none;
}

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

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    padding: 4px 10px;
    border-radius: 999px;
    background: rgba(15,23,42,0.8);
    border: 1px solid rgba(148,163,184,0.5);
    color: var(--text-soft);
    margin-bottom: 10px;
}

.hero-tag span.dot {
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: #22c55e;
    box-shadow: 0 0 10px #22c55e;
}

.hero h2 {
    font-size: 26px;
    line-height: 1.2;
    margin-bottom: 10px;
}

.hero h2 .highlight {
    background: linear-gradient(to right, #38bdf8, #22c55e);
    -webkit-background-clip: text;
    color: transparent;
}

.hero p {
    font-size: 14px;
    color: var(--text-soft);
    max-width: 540px;
    line-height: 1.6;
}

.hero-actions {
    margin-top: 16px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

/* BUTTONS */
.btn-primary,
.btn-ghost {
    border-radius: 999px;
    font-size: 13px;
    padding: 8px 16px;
    border: 1px solid transparent;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    transition: all 0.18s ease-out;
}

.btn-primary {
    background: linear-gradient(135deg, #0ea5e9, #22c55e);
    color: #0b1120;
    font-weight: 600;
    box-shadow: 0 12px 35px rgba(56,189,248,0.65);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 16px 40px rgba(56,189,248,0.8);
}

.btn-ghost {
    border-color: rgba(148,163,184,0.5);
    color: var(--text-soft);
    background: rgba(15,23,42,0.8);
}

.btn-ghost:hover {
    color: var(--primary);
    border-color: var(--primary);
    transform: translateY(-1px);
}

/* SECTION TITLE */
.section-title {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.section-title .bar {
    height: 1px;
    flex: 1;
    background: linear-gradient(to right, rgba(148,163,184,0.8), transparent);
}

/* POST LIST */
.post-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.post-card {
    border-radius: var(--radius-lg);
    background: #020617;
    border: 1px solid rgba(31,41,55,0.9);
    padding: 12px 14px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    transition: all 0.18s ease-out;
}

.post-card:hover {
    border-color: var(--primary);
    box-shadow: 0 16px 35px rgba(15,23,42,0.9);
    transform: translateY(-1px);
}

.post-meta {
    display: flex;
    gap: 8px;
    font-size: 11px;
    color: var(--text-soft);
    flex-wrap: wrap;
}

.post-meta span {
    padding: 2px 8px;
    border-radius: 999px;
    background: rgba(15,23,42,0.95);
    border: 1px solid rgba(31,41,55,0.9);
}

.post-title {
    font-size: 15px;
    font-weight: 600;
}

/* Link tiêu đề bài viết */
.post-title a {
    color: inherit;
    text-decoration: none;
}

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

.post-excerpt {
    font-size: 13px;
    color: var(--text-soft);
    line-height: 1.5;
}

/* SIDEBAR */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.card {
    background: rgba(15,23,42,0.95);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(31,41,55,0.9);
    padding: 14px 16px;
    backdrop-filter: blur(16px);
}

.card h3 {
    font-size: 14px;
    margin-bottom: 8px;
}

.card p {
    font-size: 13px;
    color: var(--text-soft);
    line-height: 1.6;
}

.about-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 10px;
}

.about-tags span {
    font-size: 11px;
    padding: 4px 8px;
    border-radius: 999px;
    border: 1px solid rgba(55,65,81,0.9);
    background: rgba(15,23,42,0.95);
    color: var(--text-soft);
}

/* SOCIAL LIST */
.social-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 13px;
}

.social-list a {
    text-decoration: none;
    color: var(--text-soft);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 7px 0;
    border-bottom: 1px dashed rgba(55,65,81,0.8);
}

.social-list a .icon {
    font-size: 12px;
    opacity: 0.8;
}

.social-list a:last-child {
    border-bottom: none;
}

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

/* FOOTER */
footer {
    margin-top: 26px;
    font-size: 11px;
    text-align: center;
    color: var(--text-soft);
}

footer a {
    color: var(--primary);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}
/* CHỦ ĐỀ (TOPICS) */
.topics {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 10px;
}

.topic-chip {
    font-size: 12px;
    padding: 6px 12px;
    border-radius: 999px;
    border: 1px solid rgba(148,163,184,0.4);
    color: var(--text-soft);
    text-decoration: none;
    background: rgba(15,23,42,0.9);
    transition: all 0.16s ease-out;
}

.topic-chip:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-1px);
}

.topic-chip.active {
    background: linear-gradient(135deg, #0ea5e9, #22c55e);
    color: #0b1120;
    border-color: transparent;
}

/* DOWNLOAD LIST */
.downloads-card {
    font-size: 13px;
}

.download-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.download-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px 0;
    border-bottom: 1px dashed rgba(55,65,81,0.8);
}

.download-list li:last-child {
    border-bottom: none;
}

.download-list a {
    color: var(--text);
    text-decoration: none;
}

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

.download-list .size {
    font-size: 11px;
    color: var(--text-soft);
    margin-left: 12px;
}