/* ===== CSS VARIABLES ===== */
:root {
    /* Dark Theme Colors */
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --bg-hover: #30363d;

    /* Text Colors */
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;

    /* Accent Colors */
    --accent-primary: #58a6ff;
    --accent-hover: #79b8ff;
    --accent-green: #3fb950;
    --accent-red: #f85149;
    --accent-yellow: #d29922;

    /* Border */
    --border-color: #30363d;
    --border-light: #21262d;

    /* Bullish/Bearish */
    --bullish-bg: #238636;
    --bullish-light: #2ea043;
    --bearish-bg: #da3633;
    --bearish-light: #f85149;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* ===== HEADER ===== */
header {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    border-bottom: 1px solid var(--border-color);
    padding: 32px 20px;
    text-align: center;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

header .subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* ===== MAIN CONTAINER ===== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px 20px;
}

/* ===== TABS NAVIGATION ===== */
.tabs {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 6px;
    margin-bottom: 24px;
    display: flex;
    justify-content: center;
    gap: 4px;
}

.tabs > div {
    display: flex;
    gap: 4px;
}

.tab-link {
    background-color: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-link:hover {
    background-color: var(--bg-hover);
    color: var(--text-primary);
}

.tab-link.active {
    background-color: var(--accent-primary);
    color: #ffffff;
}

/* ===== TAB CONTENT ===== */
.tab-content {
    display: none;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab-content h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

/* ===== TABLE STYLES ===== */
#crypto-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    font-size: 14px;
    border-radius: var(--radius-md);
    overflow: hidden;
}

#crypto-table thead th {
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 11px;
    letter-spacing: 0.5px;
    padding: 14px 12px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

#crypto-table thead th:first-child {
    text-align: left;
    padding-left: 16px;
}

#crypto-table thead th:last-child {
    position: relative;
}

#crypto-table thead th:last-child::after {
    content: 'Source: Delta Exchange';
    position: absolute;
    top: -20px;
    right: 0;
    font-size: 10px;
    font-weight: 400;
    color: var(--text-muted);
    text-transform: none;
    letter-spacing: normal;
}

#crypto-table tbody tr {
    transition: background-color var(--transition-fast);
}

#crypto-table tbody tr:hover {
    background-color: var(--bg-hover);
}

#crypto-table tbody td {
    padding: 12px;
    text-align: center;
    border-bottom: 1px solid var(--border-light);
    transition: all var(--transition-normal);
}

#crypto-table tbody tr:last-child td {
    border-bottom: none;
}

.asset-name {
    text-align: left !important;
    font-weight: 600;
    color: var(--accent-primary);
    padding-left: 16px !important;
    cursor: pointer;
}

.asset-name:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* ===== WATCHLIST SECTION ===== */
.watchlist-form {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
}

.autocomplete-container {
    position: relative;
    flex: 1;
    max-width: 400px;
}

.watchlist-form input {
    width: 100%;
    padding: 12px 16px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 14px;
    transition: all var(--transition-fast);
}

.watchlist-form input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
}

.watchlist-form input::placeholder {
    color: var(--text-muted);
}

#add-symbol-button {
    padding: 12px 20px;
    background-color: var(--accent-primary);
    color: #ffffff;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

#add-symbol-button:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

#add-symbol-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Suggestions Dropdown */
.suggestions-container {
    display: none;
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    max-height: 200px;
    overflow-y: auto;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

.suggestion-item {
    padding: 12px 16px;
    cursor: pointer;
    transition: background-color var(--transition-fast);
    font-size: 14px;
}

.suggestion-item:hover {
    background-color: var(--bg-hover);
}

/* Watchlist List */
#watchlist-list {
    list-style: none;
}

#watchlist-list li {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 16px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 8px;
    transition: all var(--transition-fast);
}

#watchlist-list li:hover {
    border-color: var(--accent-primary);
}

.remove-symbol-btn {
    background-color: var(--bearish-bg);
    color: #ffffff;
    border: none;
    width: 28px;
    height: 28px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-symbol-btn:hover {
    background-color: var(--bearish-light);
    transform: scale(1.05);
}

/* ===== SETTINGS SECTION ===== */
#Settings h2 {
    border-bottom: 1px solid var(--border-color);
}

.settings-group {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 20px;
}

.settings-group h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.settings-group p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-primary);
}

.checkbox-item input {
    display: none;
}

.checkbox-item .checkbox-box {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    background-color: var(--bg-secondary);
}

.checkbox-item .checkbox-box::after {
    content: '';
    width: 10px;
    height: 10px;
    background-color: var(--accent-primary);
    border-radius: 2px;
    opacity: 0;
    transform: scale(0);
    transition: all var(--transition-fast);
}

.checkbox-item input:checked + .checkbox-box {
    border-color: var(--accent-primary);
}

.checkbox-item input:checked + .checkbox-box::after {
    opacity: 1;
    transform: scale(1);
}

.checkbox-item:hover .checkbox-box {
    border-color: var(--accent-primary);
}

/* Buttons */
.button-primary {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background-color: var(--accent-primary);
    color: #ffffff;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: none;
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.button-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.button-primary svg {
    width: 18px;
    height: 18px;
}

.button-secondary {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.button-secondary:hover {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--text-muted);
}

#save-settings-button {
    background-color: var(--accent-green);
    color: #ffffff;
    border: none;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all var(--transition-fast);
    margin-top: 8px;
}

#save-settings-button:hover {
    background-color: #46c75b;
    transform: translateY(-1px);
}

#save-settings-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.feedback-message {
    margin-top: 12px;
    color: var(--accent-green);
    font-weight: 500;
    font-size: 14px;
}

/* PIN Container */
.pin-container {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.pin-container p {
    margin-bottom: 12px;
}

.pin-display {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 12px;
}

#pin-code-text {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    letter-spacing: 4px;
    background-color: var(--bg-secondary);
    padding: 8px 20px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    font-family: 'Courier New', monospace;
}

.copy-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 14px;
}

.copy-button:hover {
    background-color: var(--bg-hover);
    border-color: var(--accent-primary);
}

.pin-expiry-note {
    font-size: 13px !important;
    color: var(--text-muted) !important;
    font-style: italic;
}

/* ===== ALERTS LOG ===== */
.alerts-log {
    margin-top: 24px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px;
    max-height: 250px;
    overflow-y: auto;
}

.alerts-log h2 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.alerts-log ul {
    list-style: none;
}

.alerts-log li {
    padding: 10px 12px;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    font-size: 13px;
    color: var(--text-secondary);
    border-left: 3px solid var(--accent-primary);
    transition: opacity 0.5s ease-out;
}

.alerts-log li.fade-out {
    opacity: 0;
}

/* ===== LOADING & ERROR ===== */
.spinner-container {
    display: none;
    text-align: center;
    padding: 40px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto;
}

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

.error-container {
    color: var(--accent-red);
    background-color: rgba(248, 81, 73, 0.1);
    border: 1px solid var(--accent-red);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    margin-top: 16px;
    font-size: 14px;
    display: none;
}

/* ===== FOOTER ===== */
footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 32px 20px;
    margin-top: 40px;
    text-align: center;
}

.footer-content {
    max-width: 500px;
    margin: 0 auto;
}

.footer-content p {
    margin: 6px 0;
    font-size: 13px;
    color: var(--text-muted);
}

.footer-content .designed-by a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-content .designed-by a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

.footer-content .copyright {
    margin-top: 8px;
    font-size: 12px;
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ===== RESPONSIVE DESIGN ===== */
@media screen and (max-width: 768px) {
    header {
        padding: 24px 16px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    header .subtitle {
        font-size: 0.875rem;
    }

    .container {
        padding: 16px 12px;
    }

    .tabs {
        padding: 4px;
    }

    .tabs > div {
        width: 100%;
    }

    .tab-link {
        flex: 1;
        padding: 10px 12px;
        font-size: 13px;
        text-align: center;
    }

    .tab-content {
        padding: 16px;
    }

    .tab-content h2 {
        font-size: 1.1rem;
    }

    /* Table responsive */
    #crypto-table thead th,
    #crypto-table tbody td {
        padding: 10px 6px;
        font-size: 12px;
    }

    #crypto-table thead th:last-child::after {
        display: none;
    }

    .desktop-only {
        display: none;
    }

    /* Watchlist responsive */
    .watchlist-form {
        flex-direction: column;
    }

    .autocomplete-container {
        max-width: 100%;
    }

    #add-symbol-button {
        width: 100%;
    }

    /* Settings responsive */
    .settings-group {
        padding: 16px;
    }

    .checkbox-group {
        gap: 12px;
    }

    .checkbox-item {
        font-size: 13px;
    }

    .button-primary,
    #save-settings-button {
        width: 100%;
        justify-content: center;
    }

    .pin-display {
        flex-direction: column;
        align-items: flex-start;
    }

    #pin-code-text {
        font-size: 1.5rem;
    }

    /* Alerts responsive */
    .alerts-log {
        padding: 16px;
        max-height: 200px;
    }

    .alerts-log li {
        font-size: 12px;
        padding: 8px 10px;
    }

    /* Footer responsive */
    footer {
        padding: 24px 16px;
        margin-top: 24px;
    }
}

@media screen and (max-width: 480px) {
    header h1 {
        font-size: 1.25rem;
    }

    .tab-link {
        padding: 8px 8px;
        font-size: 12px;
    }

    #crypto-table thead th,
    #crypto-table tbody td {
        padding: 8px 4px;
        font-size: 11px;
    }

    .asset-name {
        padding-left: 8px !important;
    }
}