:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #0f172a;
    --text-muted: #475569;
    --border-color: #cbd5e1;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 1.1rem;
    line-height: 1.7;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 16px;
}

/* Header & Breadcrumb */
.main-header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 18px 0;
}

.brand-logo {
    font-size: 1.65rem;
    font-weight: 800;
    color: var(--primary-color);
    text-decoration: none;
}

.brand-logo span {
    color: var(--text-color);
}

.breadcrumb-nav {
    padding: 14px 0;
    font-size: 0.95rem;
}

.breadcrumb {
    display: flex;
    list-style: none;
    gap: 8px;
    color: var(--text-muted);
}

.breadcrumb li::after {
    content: "/";
    margin-left: 8px;
}

.breadcrumb li:last-child::after {
    content: "";
}

.breadcrumb a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

/* Layout Content */
.tool-intro {
    margin: 20px 0;
}

.tool-intro h1 {
    font-size: 1.85rem;
    margin-bottom: 8px;
}

.tool-intro p {
    color: var(--text-muted);
}

.calculator-card {
    background: var(--card-bg);
    padding: 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    margin-bottom: 32px;
}

.input-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-bottom: 24px;
}

@media (min-width: 600px) {
    .input-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.input-field label {
    display: block;
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.input-field input,
.input-field select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    outline: none;
}

.input-field input:focus,
.input-field select:focus {
    border-color: var(--primary-color);
}

/* Results Display */
.results-section h2 {
    font-size: 1.15rem;
    margin-bottom: 16px;
    border-top: 1px solid var(--border-color);
    padding-top: 18px;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}

.result-card {
    background: var(--bg-color);
    padding: 14px 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.result-card.highlight {
    background: #eff6ff;
    border-color: #bfdbfe;
}

.result-card .label {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: block;
}

.result-card .value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.analysis-card {
    background: #f8fafc;
    border: 1px solid var(--border-color);
    border-left: 5px solid var(--primary-color);
    padding: 16px 20px;
    border-radius: 8px;
    margin-bottom: 16px;
}

.analysis-card h3 {
    font-size: 1.05rem;
    margin-bottom: 6px;
}

.analysis-card p {
    font-size: 0.975rem;
    line-height: 1.6;
}

.hoki-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

@media (min-width: 600px) {
    .hoki-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.hoki-box {
    background: #ffffff;
    border: 1px solid var(--border-color);
    padding: 12px 16px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.95rem;
}

.hoki-box .icon {
    font-size: 1.8rem;
}

/* SEO Article */
.seo-article {
    background: var(--card-bg);
    padding: 28px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    margin-bottom: 40px;
}

.seo-article h2, .seo-article h3 {
    margin: 20px 0 10px 0;
}

/* Footer */
.main-footer {
    text-align: center;
    padding: 28px 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.95rem;
}