:root {
    --bg-deep: #0f172a;
    --bg-surface: #1e293b;
    --accent-primary: #38bdf8;
    --accent-secondary: #2dd4bf;
    --text-main: #f1f5f9;
    --text-dim: #94a3b8;
    --glass-bg: rgba(30, 41, 59, 0.8);
    --border-color: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --container-width: 1300px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Plus Jakarta Sans', 'Noto Sans TC', -apple-system, sans-serif;
    background-color: var(--bg-deep);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* --- Layout --- */
.section-padding { padding: 6rem 5%; max-width: var(--container-width); margin: 0 auto; }
.section-header { text-align: center; margin-bottom: 4rem; }
.section-header h2 { font-size: 2.5rem; font-weight: 800; margin-bottom: 1rem; letter-spacing: -0.02em; }
.section-header p { color: var(--text-dim); font-size: 1.1rem; }

/* --- Components --- */
.btn-primary {
    display: inline-block;
    background: var(--accent-primary);
    color: var(--bg-deep);
    padding: 0.9rem 1.8rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 700;
    transition: var(--transition);
    box-shadow: 0 10px 20px rgba(56, 189, 248, 0.2);
    border: none;
    cursor: pointer;
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 15px 30px rgba(56, 189, 248, 0.3); }

.btn-secondary {
    display: inline-block;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
    padding: 0.9rem 1.8rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.btn-secondary:hover { background: rgba(255, 255, 255, 0.1); border-color: var(--text-dim); }

/* --- Header --- */
header {
    position: fixed;
    top: 0; width: 100%;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.header-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 1rem 5%;
    position: relative;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: baseline;
    gap: 0.45rem;
    line-height: 1.15;
}

.logo-title,
.logo-subtitle {
    display: inline-block;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-title {
    font-size: 1.5rem;
    line-height: 1.15;
    padding-bottom: 0.08em;
}

.logo-subtitle {
    font-size: 0.78rem;
    letter-spacing: 0.12em;
    line-height: 1.1;
}

/* Desktop Nav */
nav {
    display: flex;
    gap: 2rem;
    align-items: center;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}
nav a { text-decoration: none; color: var(--text-dim); font-weight: 600; font-size: 0.95rem; transition: var(--transition); }
nav a:hover, nav a.active { color: var(--accent-primary); }

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    background: none;
    border: none;
}
.menu-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-main);
    border-radius: 2px;
    transition: var(--transition);
}

@media (max-width: 820px) {
    .menu-toggle { display: flex; order: 2; }
    .logo { order: 1; }
    
    nav {
        position: fixed; top: 0; right: 0;
        width: 100%; height: 100vh;
        background: var(--bg-deep);
        flex-direction: column; justify-content: center;
        gap: 2.5rem; left: auto; transform: translateX(100%);
        transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 1050;
    }
    nav.is-open { transform: translateX(0); }
    nav a { font-size: 1.25rem; }
}

/* --- Footer --- */
footer { padding: 4rem 5%; border-top: 1px solid var(--border-color); text-align: center; color: var(--text-dim); font-size: 0.9rem; }

/* --- Animations --- */
.fade-in { animation: fadeIn 0.8s ease-out forwards; opacity: 0; transform: translateY(20px); }
@keyframes fadeIn { to { opacity: 1; transform: translateY(0); } }

/* --- Bento Grid --- */
.bento-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.bento-item { background: var(--bg-surface); border: 1px solid var(--border-color); border-radius: 24px; padding: 2.5rem; transition: var(--transition); }
.bento-item:hover { border-color: var(--accent-primary); transform: translateY(-5px); }
.bento-item.large { grid-column: span 2; }

@media (max-width: 1024px) {
    .bento-grid { grid-template-columns: 1fr; }
    .bento-item.large { grid-column: span 1; }
}