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

body {
    background-color: #0d1117;
    color: #e6edf3;
    font-family: 'Malgun Gothic', 'Apple SD Gothic Neo', sans-serif;
    min-height: 100vh;
}

/* ── Header ── */
header {
    background-color: #161b22;
    border-bottom: 1px solid #30363d;
    padding: 16px 24px;
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}

.title-group h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #ffffff;
}

.ticker {
    font-size: 0.85rem;
    color: #8b949e;
    margin-left: 8px;
}

.price-group {
    display: flex;
    align-items: baseline;
    gap: 12px;
}

.current-price {
    font-size: 2rem;
    font-weight: 700;
    color: #ffffff;
}

.price-change {
    font-size: 1rem;
    font-weight: 600;
}

/* ── Main Layout ── */
main {
    max-width: 1200px;
    margin: 24px auto;
    padding: 0 16px;
    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    gap: 16px;
}

/* ── Cards ── */
.card {
    background-color: #161b22;
    border: 1px solid #30363d;
    border-radius: 10px;
    padding: 20px;
}

.chart-card {
    grid-column: 1 / -1;
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 8px;
}

.card h2 {
    font-size: 1rem;
    font-weight: 600;
    color: #c9d1d9;
    margin-bottom: 16px;
}

.card-header h2 {
    margin-bottom: 0;
}

/* ── Period Buttons ── */
.period-buttons {
    display: flex;
    gap: 6px;
}

.period-btn {
    background: #21262d;
    border: 1px solid #30363d;
    border-radius: 6px;
    color: #8b949e;
    cursor: pointer;
    font-size: 0.8rem;
    padding: 4px 10px;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.period-btn:hover {
    background: #30363d;
    color: #c9d1d9;
}

.period-btn.active {
    background: #1f6feb;
    border-color: #1f6feb;
    color: #ffffff;
}

/* ── Chart containers ── */
#chart-container {
    width: 100%;
    height: 380px;
    border-radius: 6px;
    overflow: hidden;
}

#volume-container {
    width: 100%;
    height: 100px;
    margin-top: 4px;
    border-radius: 6px;
    overflow: hidden;
}

.chart-legend {
    display: flex;
    gap: 16px;
    margin-top: 10px;
    font-size: 0.8rem;
}

.legend-item {
    color: #8b949e;
}

/* ── Bottom Info Cards ── */
.bottom-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.info-card {
    /* inherits .card */
}

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

.info-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.company-table {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.company-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #21262d;
    padding-bottom: 8px;
    font-size: 0.9rem;
}

.company-row:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.label {
    font-size: 0.8rem;
    color: #8b949e;
}

.value {
    font-size: 0.95rem;
    font-weight: 600;
    color: #e6edf3;
}

/* ── Colors ── */
.up   { color: #ff4b4b; }
.down { color: #4b8fff; }
.flat { color: #8b949e; }

/* ── Chart wrapper / overlay ── */
.chart-wrapper {
    position: relative;
}

.chart-overlay {
    position: absolute;
    inset: 0;
    z-index: 10;
    background: #161b22;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: #8b949e;
    font-size: 0.9rem;
    border-radius: 6px;
    text-align: center;
    line-height: 1.6;
}

.chart-overlay.error {
    color: #f85149;
    flex-direction: column;
    gap: 6px;
}

.chart-overlay.hidden {
    display: none;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid #30363d;
    border-top-color: #1f6feb;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    flex-shrink: 0;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.chart-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 10px;
}

.data-source {
    font-size: 0.75rem;
    color: #484f58;
}

/* ── Footer ── */
footer {
    text-align: center;
    padding: 24px 16px;
    border-top: 1px solid #21262d;
    color: #484f58;
    font-size: 0.78rem;
    line-height: 1.8;
    margin-top: 24px;
}

/* ── Responsive ── */
@media (min-width: 768px) {
    main {
        grid-template-columns: 1fr 1fr;
    }

    .chart-card {
        grid-column: 1 / -1;
    }
}