:root {
    --brand-black: #121212;
    --brand-yellow: #FFD600;
    --brand-blue: #2979FF;
    --brand-grey: #ECEFF1;
    --text-light: #F5F5F5;
    --text-muted: #B0BEC5;
    --geometric-border: 1px solid rgba(255, 214, 0, 0.3);
}

body {
    background-color: var(--brand-black);
    color: var(--text-light);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    overflow-x: hidden;
}

.mono-font {
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
}

/* 導覽列樣式 */
.navbar {
    background-color: rgba(18, 18, 18, 0.95);
    border-bottom: var(--geometric-border);
    backdrop-filter: blur(10px);
}

.navbar-brand {
    font-weight: 800;
    letter-spacing: 2px;
    color: var(--brand-yellow) !important;
}

.nav-link {
    color: var(--text-light) !important;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 1px;
    margin: 0 10px;
    transition: color 0.3s ease;
}

.nav-link:hover, .nav-link.active {
    color: var(--brand-yellow) !important;
}

/* 按鈕樣式 */
.btn-linkflow {
    background-color: var(--brand-yellow);
    color: var(--brand-black);
    border-radius: 0;
    font-weight: 700;
    text-transform: uppercase;
    padding: 12px 30px;
    border: none;
    transition: all 0.3s ease;
}

.btn-linkflow:hover {
    background-color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 214, 0, 0.4);
}

.btn-outline-linkflow {
    background-color: transparent;
    color: var(--brand-yellow);
    border: 1px solid var(--brand-yellow);
    border-radius: 0;
    padding: 12px 30px;
}

/* 幾何背景裝飾 */
.geo-grid {
    background-image: linear-gradient(rgba(255, 214, 0, 0.05) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255, 214, 0, 0.05) 1px, transparent 1px);
    background-size: 50px 50px;
}

/* 區塊標題 */
.section-title {
    border-left: 4px solid var(--brand-yellow);
    padding-left: 15px;
    margin-bottom: 40px;
    text-transform: uppercase;
    letter-spacing: 3px;
}

/* 頁尾 */
footer {
    border-top: var(--geometric-border);
    padding: 60px 0;
    background-color: #0a0a0a;
}

/* 動畫 */
@keyframes flowLine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.flow-line {
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--brand-yellow), transparent);
    width: 100%;
    position: relative;
    overflow: hidden;
}

.flow-line::after {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: inherit;
    animation: flowLine 3s infinite linear;
}