:root {
    --bg-color: #ffffff;
    --text-primary: #0a0a0a;
    --text-secondary: #737373;
    --border-color: #e5e5e5;
    --hover-bg: #f5f5f5;
    --accent-black: #000000;
    --card-bg: #f9f9f9;
    --search-bg: #f2f2f2;
    --font-sans:
        "Geist", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
        Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue",
        sans-serif;
    --font-mono: "Geist Mono", monospace;
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --text-primary: #ededed;
    --text-secondary: #a1a1a1;
    --border-color: #3f3f3f;
    --hover-bg: #2a2a2a;
    --accent-black: #ffffff;
    --card-bg: #0a0a0a;
    --search-bg: #2a2a2a;
}

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

body > main {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    font-size: 16px;
    line-height: 1.5;
    flex-direction: column;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    min-height: 100vh;
    transition:
        background 0.3s,
        color 0.3s;
}

h1 {
    font-size: 19px;
    width: 100%;
    font-weight: 500;
    margin: 0px 2px;
    padding: 0;
    color: var(--text-primary);
}

h2 {
    font-size: 13px;
    width: 100%;
    font-weight: 400;
    color: var(--text-secondary);
    margin-bottom: 16px;
    margin-top: 4px;
    margin-left: 3px;
    padding: 0;
}

li > svg {
    color: var(--text-primary);
    stroke: var(--text-primary);
    margin-right: 6px;
}

li:hover {
    background-color: var(--hover-bg);
    border-color: var(--border-color);
}

ol {
    color: var(--text-primary);
    list-style: none;
    padding-left: 0;
    margin-left: 0;
    width: 100%;
    margin-top: 6px;
}

li {
    opacity: 0;
    transform: translateY(-4px);
    animation: item-in 140ms ease-out forwards;

    font-size: 14px;
    display: flex;
    column-gap: 4px;
    align-items: center;
    padding: 8px 10px;
    width: 100%;
    border: 1px solid transparent;
    border-radius: 8px;
    color: var(--text-primary);
}

@keyframes item-in {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

li > :last-child {
    margin-left: auto;
}

input,
textarea,
select {
    caret-color: var(--text-primary);
    font-family: inherit;
}

.main-ui {
    padding-top: 35vh;
    max-width: 480px;
    width: 100%;
}

#search-area {
    display: flex;
    justify-content: center;
    flex-direction: column;
    align-items: start;
    max-width: 540px;
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
}

form {
    width: 100%;
    margin: 0;
    padding: 0;
}

#search-bar {
    width: 100%;
    background-color: transparent;
    border: none;
    font-size: 14px;
    font-weight: 400;
    padding: 0px 0px;
    color: var(--text-primary);
}

#search-bar:focus {
    outline: none;
}

.search-bar-container {
    display: flex;
    align-items: center;
    justify-content: left;
    column-gap: 0.7rem;
    background-color: var(--search-bg);
    border: 1px solid var(--border-color);
    padding: 10px 10px;
    border-radius: 8px;
    color: var(--text-primary);
}

.search-bar-container svg {
    color: var(--text-secondary);
}

#search-bar::placeholder {
    color: var(--text-secondary);
}

fieldset {
    border-style: none;
}

#upload-dialog {
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--bg-color);
    color: var(--text-primary);
    box-shadow: none;
    width: 100%;
    max-width: 520px;
    margin: auto;
}

#upload-dialog::backdrop {
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(2px);
}

#upload-dialog:focus {
    outline: none;
}

.form-group {
    margin-bottom: 12px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input,
.form-group select {
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: transparent;
    color: var(--text-primary);
    font-size: 14px;
    width: 100%;
    height: 38px;
    box-sizing: border-box;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--text-primary);
}

.form-row {
    display: flex;
    gap: 12px;
}

.form-row .form-group {
    flex: 1;
}

.file-trigger {
    height: 80px;
    padding: 0 14px;
    margin: 8px 0 16px;

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    border-radius: 8px;
    border: 1px dashed var(--border-color);

    background-color: var(--hover-bg);
    color: var(--text-secondary);

    font-size: 12px;
    font-weight: 500;
    line-height: 1.5;

    cursor: pointer;
    user-select: none;
    width: 100%;

    transition: all 0.15s ease;
}

.file-trigger:hover {
    background-color: var(--bg-color);
    border-color: var(--text-primary);
    color: var(--text-primary);
}

header {
    margin-left: auto;
    margin-right: 24px;
    margin-top: 16px;
    width: auto;
    position: absolute;
    top: 0;
    right: 0;
    display: flex;
    gap: 8px;
}

button {
    border: 1px solid var(--border-color);
    background-color: transparent;
    border-radius: 8px;
    padding: 8px 14px;
    font-size: 13px;
    display: flex;
    color: var(--text-secondary);
    column-gap: 6px;
    align-items: center;
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: var(--font-sans);
}

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

button svg {
    color: currentColor;
    stroke: currentColor;
}

menu {
    display: flex;
    justify-content: end;
    column-gap: 16px;
    align-items: center;
    margin: 0;
}

button:focus {
    outline: none;
}

.cancel-btn {
    background-color: var(--hover-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    margin: 0;
}

.cancel-btn svg {
    color: var(--text-primary);
    stroke: var(--text-primary);
}

.cancel-btn:hover {
    background-color: var(--border-color);
}

.confirm-btn {
    margin: 0;
    background-color: var(--accent-black);
    color: var(--bg-color);
    border-color: var(--accent-black);
}

.confirm-btn:hover {
    opacity: 0.9;
    background-color: var(--accent-black);
    color: var(--bg-color);
}

.confirm-btn svg {
    color: var(--bg-color);
    stroke: var(--bg-color);
}

dialog {
    padding: 24px;
}

.upload-guide,
.fileName {
    font-size: 12px;
    color: var(--text-secondary);
    display: block;
    text-align: center;
    margin-bottom: 12px;
    min-height: 18px;
}

#matched-courses {
    margin-top: 16px;
}

.course-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
    flex: 1;
}

.course-name {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.course-code {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    background: var(--hover-bg);
    padding: 2px 6px;
    border-radius: 4px;
    flex-shrink: 0;
}

.paper-count {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    min-width: 18px;
    text-align: center;
    flex-shrink: 0;
    margin-right: 4px;
}

@media (max-width: 600px) {
    main {
        padding-left: 16px;
        padding-right: 16px;
    }

    header {
        margin-right: 16px;
    }
}