/* 璀璨傳承・珠寶鑑定與全球礦區溯源總署 - 核心樣式 */
:root {
    --midnight-velvet: #0A0A0B;
    --champagne-gold: #CFB53B;
    --diamond-white: #E5E4E2;
    --emerald-green: #50C878;
    --font-serif: 'Playfair Display', serif;
    --font-sans: 'Inter', sans-serif;
}

body {
    background-color: var(--midnight-velvet);
    color: var(--diamond-white);
    font-family: var(--font-sans);
    margin: 0;
    overflow-x: hidden;
    line-height: 1.6;
}

h1, h2, h3, h4, .brand-font {
    font-family: var(--font-serif);
    letter-spacing: 0.1em;
}

.text-gold { color: var(--champagne-gold); }
.text-emerald { color: var(--emerald-green); }

/* 天鵝絨緩動背景 */
.velvet-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 50% 50%, rgba(20, 20, 25, 1) 0%, rgba(10, 10, 11, 1) 100%);
    z-index: -1;
    overflow: hidden;
}

.velvet-glow {
    position: absolute;
    width: 150%;
    height: 150%;
    background: radial-gradient(circle at center, rgba(207, 181, 59, 0.03) 0%, transparent 70%);
    top: -25%;
    left: -25%;
    animation: flow 20s infinite alternate ease-in-out;
}

@keyframes flow {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(5%, 5%) rotate(5deg); }
}

/* 導航欄樣式 */
.navbar {
    background: rgba(10, 10, 11, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(207, 181, 59, 0.2);
    padding: 1.5rem 0;
}

.navbar-brand {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--champagne-gold) !important;
    text-transform: uppercase;
}

.nav-link {
    color: var(--diamond-white) !important;
    margin: 0 1rem;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    transition: 0.3s;
}

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

/* 按鈕樣式：寶石切割感 */
.btn-gem {
    background: transparent;
    border: 1px solid var(--champagne-gold);
    color: var(--champagne-gold);
    padding: 0.8rem 2rem;
    position: relative;
    overflow: hidden;
    transition: 0.5s;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.8rem;
    border-radius: 0;
}

.btn-gem::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: 0.5s;
}

.btn-gem:hover {
    background: var(--champagne-gold);
    color: var(--midnight-velvet);
    box-shadow: 0 0 20px rgba(207, 181, 59, 0.4);
}

.btn-gem:hover::before {
    left: 100%;
}

/* 卡片樣式 */
.gem-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: 2rem;
    transition: 0.4s;
    height: 100%;
}

.gem-card:hover {
    border-color: var(--champagne-gold);
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.05);
}

/* 頁尾 */
footer {
    padding: 4rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    margin-top: 5rem;
    font-size: 0.8rem;
    color: rgba(229, 228, 226, 0.5);
}