:root {
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-card-hover: #26334a;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --border-color: rgba(255, 255, 255, 0.1);
    --success: #10b981;
}

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

body {
    font-family: 'Inter', 'Noto Sans TC', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* Background Effects */
.background-effects {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
    pointer-events: none;
}

.glow {
    position: absolute;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.15;
}

.glow-1 {
    top: -100px;
    left: -100px;
    background: var(--accent-primary);
    animation: float 10s ease-in-out infinite alternate;
}

.glow-2 {
    bottom: -100px;
    right: -100px;
    background: var(--accent-secondary);
    animation: float 12s ease-in-out infinite alternate-reverse;
}

@keyframes float {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

/* Layout */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 1.5rem;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 4rem;
    animation: slideDown 0.6s ease-out;
}

.badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent-primary);
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

.text-gradient {
    background: linear-gradient(135deg, #60a5fa, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Steps */
.steps-container {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.step-card {
    background: var(--bg-card);
    border-radius: 1.5rem;
    padding: 2.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    animation: fadeIn 0.8s ease-out backwards;
}

.step-card:nth-child(1) { animation-delay: 0.1s; }
.step-card:nth-child(2) { animation-delay: 0.2s; }
.step-card:nth-child(3) { animation-delay: 0.3s; }

.step-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 30px 60px -12px rgba(0, 0, 0, 0.3);
    border-color: rgba(255, 255, 255, 0.15);
}

.step-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.step-number {
    width: 2.5rem;
    height: 2.5rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    box-shadow: 0 4px 10px rgba(59, 130, 246, 0.3);
}

.step-card h2 {
    font-size: 1.5rem;
    font-weight: 700;
}

.step-desc {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* Code Window */
.code-window {
    background: #0b101e;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.code-window.accent {
    border-color: rgba(139, 92, 246, 0.3);
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.05);
}

.window-header {
    background: rgba(255, 255, 255, 0.03);
    padding: 0.75rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
}

.window-controls {
    display: flex;
    gap: 0.375rem;
}

.window-controls span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.window-controls span:nth-child(1) { background: #ff5f56; }
.window-controls span:nth-child(2) { background: #ffbd2e; }
.window-controls span:nth-child(3) { background: #27c93f; }

.window-title {
    font-family: monospace;
    font-size: 0.875rem;
    color: var(--text-secondary);
    flex: 1;
    text-align: center;
}

.copy-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: var(--text-primary);
    padding: 0.4rem 0.75rem;
    border-radius: 0.375rem;
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.375rem;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.copy-btn.primary {
    background: var(--accent-secondary);
}

.copy-btn.primary:hover {
    background: #7c3aed;
}

.window-content {
    padding: 1rem;
    max-height: 300px;
    overflow-y: auto;
}

.window-content::-webkit-scrollbar {
    width: 8px;
}
.window-content::-webkit-scrollbar-track {
    background: transparent;
}
.window-content::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

pre {
    margin: 0;
}

code {
    font-family: 'JetBrains Mono', 'Menlo', 'Monaco', monospace;
    font-size: 0.875rem;
    color: #e2e8f0;
    white-space: pre-wrap;
    word-break: break-word;
}

/* Day Selector */
.day-selector {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    background: rgba(255, 255, 255, 0.03);
    padding: 1rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
}

.day-selector label {
    font-weight: 500;
}

.input-group {
    display: flex;
    align-items: center;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 0.5rem;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: border-color 0.2s;
}

.input-group:focus-within {
    border-color: var(--accent-secondary);
}

.input-group .prefix {
    padding: 0.5rem 0.75rem;
    color: var(--text-secondary);
    font-weight: 600;
    background: rgba(255, 255, 255, 0.05);
}

.input-group input {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 0.75rem;
    width: 60px;
    font-size: 1rem;
    font-weight: 600;
    outline: none;
}

#dayDisplay {
    color: #fbbf24;
    font-weight: bold;
    padding: 0 0.2rem;
}

/* Output Preview */
.output-preview {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.preview-header {
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    user-select: none;
    transition: background 0.2s;
}

.preview-header:hover {
    background: rgba(255, 255, 255, 0.05);
}

.preview-header .chevron {
    transition: transform 0.3s;
}

.output-preview.open .chevron {
    transform: rotate(90deg);
}

.success-icon {
    color: var(--success);
}

.preview-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
}

.output-preview.open .preview-content {
    max-height: 400px;
    border-top: 1px solid var(--border-color);
}

.preview-content pre {
    padding: 1rem;
    font-size: 0.8125rem;
    color: #cbd5e1;
}

.hint {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    color: var(--accent-primary);
    background: rgba(59, 130, 246, 0.1);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-top: 1px solid rgba(59, 130, 246, 0.2);
}

/* Action Footer */
.action-footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.action-footer p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    color: white;
    text-decoration: none;
    padding: 1rem 2rem;
    border-radius: 999px;
    font-weight: 700;
    font-size: 1.125rem;
    box-shadow: 0 10px 25px -5px rgba(99, 102, 241, 0.4);
    transition: all 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px -5px rgba(99, 102, 241, 0.5);
    filter: brightness(1.1);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--success);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 999px;
    font-weight: 600;
    box-shadow: 0 10px 25px rgba(16, 185, 129, 0.4);
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    z-index: 50;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Animations */
@keyframes slideDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 640px) {
    .hero h1 { font-size: 2rem; }
    .step-card { padding: 1.5rem; }
    .day-selector { flex-direction: column; align-items: flex-start; }
}